Gabriel Luke

Gabriel Luke

1602332194

Beginner’s guide to style and a new wardrobe

This guide is intended for someone who has just become interested in dressing better or discovering a fresh style and wardrobe. It’ll be quite a long read, but it should be quick enough to follow the steps themselves. It also relies on current guides and other MFA resources.

Look at the names of the subsections, the bold texts, and click on some links. As a slow reader, reading this whole thing should take you approximately 15 minutes.

Most of this is just my view. Feel free to do it your own way. I hope it somehow helps you.
This is image title
It is a daunting job to buy an entirely new wardrobe. It’s also something in one go that you can stop doing. At the outset, take it easy. In terms of both the things in it, and the quality of your clothing, it can take months to even years to complete a wardrobe you are satisfied with.

When you visit a clothing shop like at lil peep merch, you do not have to buy anything. It can also be overwhelming and stressful to try and buy something at the same time, and you can end up with a variety of clothes that you will not wear that much. Perhaps because they don’t match perfectly, or because they don’t match your style or what you’re going for exactly, and there’s a myriad of other explanations for that.

Try to think of a few ways you can mix it with clothing you already own if you want to buy something, so you don’t end up with clothing you’ll never end up wearing. Tip: aim not to match the colors, but instead concentrate on complementary colors.

#fashion #lilpeepmerch #t-shirt #clothinh #lilpeepmerchandise

What is GEEK

Buddha Community

Beginner’s guide to style and a new wardrobe
Mike  Kozey

Mike Kozey

1656151740

Test_cov_console: Flutter Console Coverage Test

Flutter Console Coverage Test

This small dart tools is used to generate Flutter Coverage Test report to console

How to install

Add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):

dev_dependencies:
  test_cov_console: ^0.2.2

How to run

run the following command to make sure all flutter library is up-to-date

flutter pub get
Running "flutter pub get" in coverage...                            0.5s

run the following command to generate lcov.info on coverage directory

flutter test --coverage
00:02 +1: All tests passed!

run the tool to generate report from lcov.info

flutter pub run test_cov_console
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
 print_cov_constants.dart                    |    0.00 |    0.00 |    0.00 |    no unit testing|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Optional parameter

If not given a FILE, "coverage/lcov.info" will be used.
-f, --file=<FILE>                      The target lcov.info file to be reported
-e, --exclude=<STRING1,STRING2,...>    A list of contains string for files without unit testing
                                       to be excluded from report
-l, --line                             It will print Lines & Uncovered Lines only
                                       Branch & Functions coverage percentage will not be printed
-i, --ignore                           It will not print any file without unit testing
-m, --multi                            Report from multiple lcov.info files
-c, --csv                              Output to CSV file
-o, --output=<CSV-FILE>                Full path of output CSV file
                                       If not given, "coverage/test_cov_console.csv" will be used
-t, --total                            Print only the total coverage
                                       Note: it will ignore all other option (if any), except -m
-p, --pass=<MINIMUM>                   Print only the whether total coverage is passed MINIMUM value or not
                                       If the value >= MINIMUM, it will print PASSED, otherwise FAILED
                                       Note: it will ignore all other option (if any), except -m
-h, --help                             Show this help

example run the tool with parameters

flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

report for multiple lcov.info files (-m, --multi)

It support to run for multiple lcov.info files with the followings directory structures:
1. No root module
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
2. With root module
<root>/coverage/lcov.info
<root>/lib/src
<root>/<module_a>
<root>/<module_a>/coverage/lcov.info
<root>/<module_a>/lib/src
<root>/<module_b>
<root>/<module_b>/coverage/lcov.info
<root>/<module_b>/lib/src
...
You must run test_cov_console on <root> dir, and the report would be grouped by module, here is
the sample output for directory structure 'with root module':
flutter pub run test_cov_console --file=coverage/lcov.info --exclude=_constants,_mock --multi
---------------------------------------------|---------|---------|---------|-------------------|
File                                         |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_a -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|
---------------------------------------------|---------|---------|---------|-------------------|
File - module_b -                            |% Branch | % Funcs | % Lines | Uncovered Line #s |
---------------------------------------------|---------|---------|---------|-------------------|
lib/src/                                     |         |         |         |                   |
 print_cov.dart                              |  100.00 |  100.00 |   88.37 |...,149,205,206,207|
lib/                                         |         |         |         |                   |
 test_cov_console.dart                       |    0.00 |    0.00 |    0.00 |    no unit testing|
---------------------------------------------|---------|---------|---------|-------------------|
 All files with unit testing                 |  100.00 |  100.00 |   88.37 |                   |
---------------------------------------------|---------|---------|---------|-------------------|

Output to CSV file (-c, --csv, -o, --output)

flutter pub run test_cov_console -c --output=coverage/test_coverage.csv

#### sample CSV output file:
File,% Branch,% Funcs,% Lines,Uncovered Line #s
lib/,,,,
test_cov_console.dart,0.00,0.00,0.00,no unit testing
lib/src/,,,,
parser.dart,100.00,100.00,97.22,"97"
parser_constants.dart,100.00,100.00,100.00,""
print_cov.dart,100.00,100.00,82.91,"29,49,51,52,171,174,177,180,183,184,185,186,187,188,279,324,325,387,388,389,390,391,392,393,394,395,398"
print_cov_constants.dart,0.00,0.00,0.00,no unit testing
All files with unit testing,100.00,100.00,86.07,""

Installing

Use this package as an executable

Install it

You can install the package from the command line:

dart pub global activate test_cov_console

Use it

The package has the following executables:

$ test_cov_console

Use this package as a library

Depend on it

Run this command:

With Dart:

 $ dart pub add test_cov_console

With Flutter:

 $ flutter pub add test_cov_console

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  test_cov_console: ^0.2.2

Alternatively, your editor might support dart pub get or flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:test_cov_console/test_cov_console.dart';

example/lib/main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Author: DigitalKatalis
Source Code: https://github.com/DigitalKatalis/test_cov_console 
License: BSD-3-Clause license

#flutter #dart #test 

Abigail betty

Abigail betty

1624226400

What is Bitcoin Cash? - A Beginner’s Guide

Bitcoin Cash was created as a result of a hard fork in the Bitcoin network. The Bitcoin Cash network supports a larger block size than Bitcoin (currently 32mb as opposed to Bitcoin’s 1mb).

Later on, Bitcoin Cash forked into Bitcoin SV due to differences in how to carry on its developments.

That’s Bitcoin Cash in a nutshell. If you want a more detailed review watch the complete video. Here’s what I’ll cover:

0:50 - Bitcoin forks
2:06 - Bitcoin’s block size debate
3:35 - Big blocks camp
4:26 - Small blocks camp
5:16 - Small blocks vs. big blocks arguments
7:05 - How decisions are made in the Bitcoin network
10:14 - Block size debate resolution
11:06 - Bitcoin cash intro
11:28 - BTC vs. BCH
12:13 - Bitcoin Cash (ABC) vs. Bitcoin SV
13:09 - Conclusion
📺 The video in this post was made by 99Bitcoins
The origin of the article: https://www.youtube.com/watch?v=ONhbb4YVRLM
🔺 DISCLAIMER: The article is for information sharing. The content of this video is solely the opinions of the speaker who is not a licensed financial advisor or registered investment advisor. Not investment advice or legal advice.
Cryptocurrency trading is VERY risky. Make sure you understand these risks and that you are responsible for what you do with your money
🔥 If you’re a beginner. I believe the article below will be useful to you ☞ What You Should Know Before Investing in Cryptocurrency - For Beginner
⭐ ⭐ ⭐The project is of interest to the community. Join to Get free ‘GEEK coin’ (GEEKCASH coin)!
☞ **-----CLICK HERE-----**⭐ ⭐ ⭐
Thanks for visiting and watching! Please don’t forget to leave a like, comment and share!

#bitcoin #blockchain #bitcoin cash #what is bitcoin cash? - a beginner’s guide #what is bitcoin cash #a beginner’s guide

Justen  Hintz

Justen Hintz

1663559281

To-do List App with HTML, CSS and JavaScript

Learn how to create a to-do list app with local storage using HTML, CSS and JavaScript. Build a Todo list application with HTML, CSS and JavaScript. Learn the basics to JavaScript along with some more advanced features such as LocalStorage for saving data to the browser.

HTML:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>To Do List With Local Storage</title>
    <!-- Font Awesome Icons -->
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.2.0/css/all.min.css"
    />
    <!-- Google Fonts -->
    <link
      href="https://fonts.googleapis.com/css2?family=Poppins:wght@400;500&display=swap"
      rel="stylesheet"
    />
    <!-- Stylesheet -->
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <div class="container">
      <div id="new-task">
        <input type="text" placeholder="Enter The Task Here..." />
        <button id="push">Add</button>
      </div>
      <div id="tasks"></div>
    </div>
    <!-- Script -->
    <script src="script.js"></script>
  </body>
</html>

CSS:

* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
body {
  background-color: #0b87ff;
}
.container {
  width: 90%;
  max-width: 34em;
  position: absolute;
  transform: translate(-50%, -50%);
  top: 50%;
  left: 50%;
}
#new-task {
  position: relative;
  background-color: #ffffff;
  padding: 1.8em 1.25em;
  border-radius: 0.3em;
  box-shadow: 0 1.25em 1.8em rgba(1, 24, 48, 0.15);
  display: grid;
  grid-template-columns: 9fr 3fr;
  gap: 1em;
}
#new-task input {
  font-family: "Poppins", sans-serif;
  font-size: 1em;
  border: none;
  border-bottom: 2px solid #d1d3d4;
  padding: 0.8em 0.5em;
  color: #111111;
  font-weight: 500;
}
#new-task input:focus {
  outline: none;
  border-color: #0b87ff;
}
#new-task button {
  font-family: "Poppins", sans-serif;
  font-weight: 500;
  font-size: 1em;
  background-color: #0b87ff;
  color: #ffffff;
  outline: none;
  border: none;
  border-radius: 0.3em;
  cursor: pointer;
}
#tasks {
  background-color: #ffffff;
  position: relative;
  padding: 1.8em 1.25em;
  margin-top: 3.8em;
  width: 100%;
  box-shadow: 0 1.25em 1.8em rgba(1, 24, 48, 0.15);
  border-radius: 0.6em;
}
.task {
  background-color: #ffffff;
  padding: 0.3em 0.6em;
  margin-top: 0.6em;
  display: flex;
  align-items: center;
  border-bottom: 2px solid #d1d3d4;
  cursor: pointer;
}
.task span {
  font-family: "Poppins", sans-serif;
  font-size: 0.9em;
  font-weight: 400;
}
.task button {
  color: #ffffff;
  padding: 0.8em 0;
  width: 2.8em;
  border-radius: 0.3em;
  border: none;
  outline: none;
  cursor: pointer;
}
.delete {
  background-color: #fb3b3b;
}
.edit {
  background-color: #0b87ff;
  margin-left: auto;
  margin-right: 3em;
}
.completed {
  text-decoration: line-through;
}

Javascript:

//Initial References
const newTaskInput = document.querySelector("#new-task input");
const tasksDiv = document.querySelector("#tasks");
let deleteTasks, editTasks, tasks;
let updateNote = "";
let count;

//Function on window load
window.onload = () => {
  updateNote = "";
  count = Object.keys(localStorage).length;
  displayTasks();
};

//Function to Display The Tasks
const displayTasks = () => {
  if (Object.keys(localStorage).length > 0) {
    tasksDiv.style.display = "inline-block";
  } else {
    tasksDiv.style.display = "none";
  }

  //Clear the tasks
  tasksDiv.innerHTML = "";

  //Fetch All The Keys in local storage
  let tasks = Object.keys(localStorage);
  tasks = tasks.sort();

  for (let key of tasks) {
    let classValue = "";

    //Get all values
    let value = localStorage.getItem(key);
    let taskInnerDiv = document.createElement("div");
    taskInnerDiv.classList.add("task");
    taskInnerDiv.setAttribute("id", key);
    taskInnerDiv.innerHTML = `<span id="taskname">${key.split("_")[1]}</span>`;
    //localstorage would store boolean as string so we parse it to boolean back
    let editButton = document.createElement("button");
    editButton.classList.add("edit");
    editButton.innerHTML = `<i class="fa-solid fa-pen-to-square"></i>`;
    if (!JSON.parse(value)) {
      editButton.style.visibility = "visible";
    } else {
      editButton.style.visibility = "hidden";
      taskInnerDiv.classList.add("completed");
    }
    taskInnerDiv.appendChild(editButton);
    taskInnerDiv.innerHTML += `<button class="delete"><i class="fa-solid fa-trash"></i></button>`;
    tasksDiv.appendChild(taskInnerDiv);
  }

  //tasks completed
  tasks = document.querySelectorAll(".task");
  tasks.forEach((element, index) => {
    element.onclick = () => {
      //local storage update
      if (element.classList.contains("completed")) {
        updateStorage(element.id.split("_")[0], element.innerText, false);
      } else {
        updateStorage(element.id.split("_")[0], element.innerText, true);
      }
    };
  });

  //Edit Tasks
  editTasks = document.getElementsByClassName("edit");
  Array.from(editTasks).forEach((element, index) => {
    element.addEventListener("click", (e) => {
      //Stop propogation to outer elements (if removed when we click delete eventually rhw click will move to parent)
      e.stopPropagation();
      //disable other edit buttons when one task is being edited
      disableButtons(true);
      //update input value and remove div
      let parent = element.parentElement;
      newTaskInput.value = parent.querySelector("#taskname").innerText;
      //set updateNote to the task that is being edited
      updateNote = parent.id;
      //remove task
      parent.remove();
    });
  });

  //Delete Tasks
  deleteTasks = document.getElementsByClassName("delete");
  Array.from(deleteTasks).forEach((element, index) => {
    element.addEventListener("click", (e) => {
      e.stopPropagation();
      //Delete from local storage and remove div
      let parent = element.parentElement;
      removeTask(parent.id);
      parent.remove();
      count -= 1;
    });
  });
};

//Disable Edit Button
const disableButtons = (bool) => {
  let editButtons = document.getElementsByClassName("edit");
  Array.from(editButtons).forEach((element) => {
    element.disabled = bool;
  });
};

//Remove Task from local storage
const removeTask = (taskValue) => {
  localStorage.removeItem(taskValue);
  displayTasks();
};

//Add tasks to local storage
const updateStorage = (index, taskValue, completed) => {
  localStorage.setItem(`${index}_${taskValue}`, completed);
  displayTasks();
};

//Function To Add New Task
document.querySelector("#push").addEventListener("click", () => {
  //Enable the edit button
  disableButtons(false);
  if (newTaskInput.value.length == 0) {
    alert("Please Enter A Task");
  } else {
    //Store locally and display from local storage
    if (updateNote == "") {
      //new task
      updateStorage(count, newTaskInput.value, false);
    } else {
      //update task
      let existingCount = updateNote.split("_")[0];
      removeTask(updateNote);
      updateStorage(existingCount, newTaskInput.value, false);
      updateNote = "";
    }
    count += 1;
    newTaskInput.value = "";
  }
});

Related Videos

Build a Todo list app in HTML, CSS & JavaScript | JavaScript for Beginners tutorial

Build a Todo List App in HTML, CSS & JavaScript with LocalStorage | JavaScript for Beginners

To Do List using HTML CSS JavaScript | To Do List JavaScript

Create A Todo List App in HTML CSS & JavaScript | Todo App in JavaScript

#html #css #javascript

A Beginner’s Guide to Setting Up a Web Application with Typescript and Express

Web applications are types of software applications that run on remote servers (source). Examples of web applications can range from word processors, to file scanners, video editing tools, shopping carts, and more. Web applications can be great additions to any website; they can even function as websites themselves (Facebook, Gmail, and Udacity’s classroom are all examples of popular web applications), so understanding how to set up and implement a web application is a fantastic skill to have.

For this guide, I am assuming that you already have a basic knowledge of npmnode and whatExpress Requests and Responses are (or that you at least know what they are used for in their basic sense). Also, I assume that you know what the npm install and mkdir commands do. You have to know basic Typescript to implement — or at least know basic JavaScript to read and understand — the code below. Finally, this is the base for the backend of a web application. You still need to create a frontend application using a framework like Angular or an HTML/CSS file to make requests and display responses.

Before you start, it’s important that you create a folder in your favorite place on your computer. This can be anywhere as long as you have a sense of how you are going to find it later when you come up with an awesome project to start developing.

The Process:

Image for post

#web-development #backend #software-development #beginners-guide #beginner

Rupert  Beatty

Rupert Beatty

1667617740

Swift-style-guide: Linkedin's Official Swift Style Guide

Swift Style Guide

Make sure to read Apple's API Design Guidelines.

Specifics from these guidelines + additional remarks are mentioned below.

This guide was last updated for Swift 4.0 on February 14, 2018.

1. Code Formatting

  • 1.1 Use 4 spaces for tabs.
  • 1.2 Avoid uncomfortably long lines with a hard maximum of 160 characters per line (Xcode->Preferences->Text Editing->Page guide at column: 160 is helpful for this)
  • 1.3 Ensure that there is a newline at the end of every file.
  • 1.4 Ensure that there is no trailing whitespace anywhere (Xcode->Preferences->Text Editing->Automatically trim trailing whitespace + Including whitespace-only lines).
  • 1.5 Do not place opening braces on new lines - we use the 1TBS style.
class SomeClass {
    func someMethod() {
        if x == y {
            /* ... */
        } else if x == z {
            /* ... */
        } else {
            /* ... */
        }
    }

    /* ... */
}
  • 1.6 When writing a type for a property, constant, variable, a key for a dictionary, a function argument, a protocol conformance, or a superclass, don't add a space before the colon.
// specifying type
let pirateViewController: PirateViewController

// dictionary syntax (note that we left-align as opposed to aligning colons)
let ninjaDictionary: [String: AnyObject] = [
    "fightLikeDairyFarmer": false,
    "disgusting": true
]

// declaring a function
func myFunction<T, U: SomeProtocol>(firstArgument: U, secondArgument: T) where T.RelatedType == U {
    /* ... */
}

// calling a function
someFunction(someArgument: "Kitten")

// superclasses
class PirateViewController: UIViewController {
    /* ... */
}

// protocols
extension PirateViewController: UITableViewDataSource {
    /* ... */
}
  • 1.7 In general, there should be a space following a comma.
let myArray = [1, 2, 3, 4, 5]
  • 1.8 There should be a space before and after a binary operator such as +, ==, or ->. There should also not be a space after a ( and before a ).
let myValue = 20 + (30 / 2) * 3
if 1 + 1 == 3 {
    fatalError("The universe is broken.")
}
func pancake(with syrup: Syrup) -> Pancake {
    /* ... */
}
  • 1.9 We follow Xcode's recommended indentation style (i.e. your code should not change if CTRL-I is pressed). When declaring a function that spans multiple lines, prefer using that syntax to which Xcode, as of version 7.3, defaults.
// Xcode indentation for a function declaration that spans multiple lines
func myFunctionWithManyParameters(parameterOne: String,
                                  parameterTwo: String,
                                  parameterThree: String) {
    // Xcode indents to here for this kind of statement
    print("\(parameterOne) \(parameterTwo) \(parameterThree)")
}

// Xcode indentation for a multi-line `if` statement
if myFirstValue > (mySecondValue + myThirdValue)
    && myFourthValue == .someEnumValue {

    // Xcode indents to here for this kind of statement
    print("Hello, World!")
}
  • 1.10 When calling a function that has many parameters, put each argument on a separate line with a single extra indentation.
someFunctionWithManyArguments(
    firstArgument: "Hello, I am a string",
    secondArgument: resultFromSomeFunction(),
    thirdArgument: someOtherLocalProperty)
  • 1.11 When dealing with an implicit array or dictionary large enough to warrant splitting it into multiple lines, treat the [ and ] as if they were braces in a method, if statement, etc. Closures in a method should be treated similarly.
someFunctionWithABunchOfArguments(
    someStringArgument: "hello I am a string",
    someArrayArgument: [
        "dadada daaaa daaaa dadada daaaa daaaa dadada daaaa daaaa",
        "string one is crazy - what is it thinking?"
    ],
    someDictionaryArgument: [
        "dictionary key 1": "some value 1, but also some more text here",
        "dictionary key 2": "some value 2"
    ],
    someClosure: { parameter1 in
        print(parameter1)
    })
  • 1.12 Prefer using local constants or other mitigation techniques to avoid multi-line predicates where possible.
// PREFERRED
let firstCondition = x == firstReallyReallyLongPredicateFunction()
let secondCondition = y == secondReallyReallyLongPredicateFunction()
let thirdCondition = z == thirdReallyReallyLongPredicateFunction()
if firstCondition && secondCondition && thirdCondition {
    // do something
}

// NOT PREFERRED
if x == firstReallyReallyLongPredicateFunction()
    && y == secondReallyReallyLongPredicateFunction()
    && z == thirdReallyReallyLongPredicateFunction() {
    // do something
}

2. Naming

2.1 There is no need for Objective-C style prefixing in Swift (e.g. use just GuybrushThreepwood instead of LIGuybrushThreepwood).

2.2 Use PascalCase for type names (e.g. struct, enum, class, typedef, associatedtype, etc.).

2.3 Use camelCase (initial lowercase letter) for function, method, property, constant, variable, argument names, enum cases, etc.

2.4 When dealing with an acronym or other name that is usually written in all caps, actually use all caps in any names that use this in code. The exception is if this word is at the start of a name that needs to start with lowercase - in this case, use all lowercase for the acronym.

// "HTML" is at the start of a constant name, so we use lowercase "html"
let htmlBodyContent: String = "<p>Hello, World!</p>"
// Prefer using ID to Id
let profileID: Int = 1
// Prefer URLFinder to UrlFinder
class URLFinder {
    /* ... */
}
  • 2.5 All constants that are instance-independent should be static. All such static constants should be placed in a marked section of their class, struct, or enum. For classes with many constants, you should group constants that have similar or the same prefixes, suffixes and/or use cases.
// PREFERRED    
class MyClassName {
    // MARK: - Constants
    static let buttonPadding: CGFloat = 20.0
    static let indianaPi = 3
    static let shared = MyClassName()
}

// NOT PREFERRED
class MyClassName {
    // Don't use `k`-prefix
    static let kButtonPadding: CGFloat = 20.0

    // Don't namespace constants
    enum Constant {
        static let indianaPi = 3
    }
}
  • 2.6 For generics and associated types, use a PascalCase word that describes the generic. If this word clashes with a protocol that it conforms to or a superclass that it subclasses, you can append a Type suffix to the associated type or generic name.
class SomeClass<Model> { /* ... */ }
protocol Modelable {
    associatedtype Model
}
protocol Sequence {
    associatedtype IteratorType: Iterator
}
  • 2.7 Names should be descriptive and unambiguous.
// PREFERRED
class RoundAnimatingButton: UIButton { /* ... */ }

// NOT PREFERRED
class CustomButton: UIButton { /* ... */ }
  • 2.8 Do not abbreviate, use shortened names, or single letter names.
// PREFERRED
class RoundAnimatingButton: UIButton {
    let animationDuration: NSTimeInterval

    func startAnimating() {
        let firstSubview = subviews.first
    }

}

// NOT PREFERRED
class RoundAnimating: UIButton {
    let aniDur: NSTimeInterval

    func srtAnmating() {
        let v = subviews.first
    }
}
  • 2.9 Include type information in constant or variable names when it is not obvious otherwise.
// PREFERRED
class ConnectionTableViewCell: UITableViewCell {
    let personImageView: UIImageView

    let animationDuration: TimeInterval

    // it is ok not to include string in the ivar name here because it's obvious
    // that it's a string from the property name
    let firstName: String

    // though not preferred, it is OK to use `Controller` instead of `ViewController`
    let popupController: UIViewController
    let popupViewController: UIViewController

    // when working with a subclass of `UIViewController` such as a table view
    // controller, collection view controller, split view controller, etc.,
    // fully indicate the type in the name.
    let popupTableViewController: UITableViewController

    // when working with outlets, make sure to specify the outlet type in the
    // property name.
    @IBOutlet weak var submitButton: UIButton!
    @IBOutlet weak var emailTextField: UITextField!
    @IBOutlet weak var nameLabel: UILabel!

}

// NOT PREFERRED
class ConnectionTableViewCell: UITableViewCell {
    // this isn't a `UIImage`, so shouldn't be called image
    // use personImageView instead
    let personImage: UIImageView

    // this isn't a `String`, so it should be `textLabel`
    let text: UILabel

    // `animation` is not clearly a time interval
    // use `animationDuration` or `animationTimeInterval` instead
    let animation: TimeInterval

    // this is not obviously a `String`
    // use `transitionText` or `transitionString` instead
    let transition: String

    // this is a view controller - not a view
    let popupView: UIViewController

    // as mentioned previously, we don't want to use abbreviations, so don't use
    // `VC` instead of `ViewController`
    let popupVC: UIViewController

    // even though this is still technically a `UIViewController`, this property
    // should indicate that we are working with a *Table* View Controller
    let popupViewController: UITableViewController

    // for the sake of consistency, we should put the type name at the end of the
    // property name and not at the start
    @IBOutlet weak var btnSubmit: UIButton!
    @IBOutlet weak var buttonSubmit: UIButton!

    // we should always have a type in the property name when dealing with outlets
    // for example, here, we should have `firstNameLabel` instead
    @IBOutlet weak var firstName: UILabel!
}

2.10 When naming function arguments, make sure that the function can be read easily to understand the purpose of each argument.

2.11 As per Apple's API Design Guidelines, a protocol should be named as nouns if they describe what something is doing (e.g. Collection) and using the suffixes able, ible, or ing if it describes a capability (e.g. Equatable, ProgressReporting). If neither of those options makes sense for your use case, you can add a Protocol suffix to the protocol's name as well. Some example protocols are below.

// here, the name is a noun that describes what the protocol does
protocol TableViewSectionProvider {
    func rowHeight(at row: Int) -> CGFloat
    var numberOfRows: Int { get }
    /* ... */
}

// here, the protocol is a capability, and we name it appropriately
protocol Loggable {
    func logCurrentState()
    /* ... */
}

// suppose we have an `InputTextView` class, but we also want a protocol
// to generalize some of the functionality - it might be appropriate to
// use the `Protocol` suffix here
protocol InputTextViewProtocol {
    func sendTrackingEvent()
    func inputText() -> String
    /* ... */
}

3. Coding Style

3.1 General

3.1.1 Prefer let to var whenever possible.

3.1.2 Prefer the composition of map, filter, reduce, etc. over iterating when transforming from one collection to another. Make sure to avoid using closures that have side effects when using these methods.

// PREFERRED
let stringOfInts = [1, 2, 3].flatMap { String($0) }
// ["1", "2", "3"]

// NOT PREFERRED
var stringOfInts: [String] = []
for integer in [1, 2, 3] {
    stringOfInts.append(String(integer))
}

// PREFERRED
let evenNumbers = [4, 8, 15, 16, 23, 42].filter { $0 % 2 == 0 }
// [4, 8, 16, 42]

// NOT PREFERRED
var evenNumbers: [Int] = []
for integer in [4, 8, 15, 16, 23, 42] {
    if integer % 2 == 0 {
        evenNumbers.append(integer)
    }
}

3.1.3 Prefer not declaring types for constants or variables if they can be inferred anyway.

3.1.4 If a function returns multiple values, prefer returning a tuple to using inout arguments (it’s best to use labeled tuples for clarity on what you’re returning if it is not otherwise obvious). If you use a certain tuple more than once, consider using a typealias. If you’re returning 3 or more items in a tuple, consider using a struct or class instead.

func pirateName() -> (firstName: String, lastName: String) {
    return ("Guybrush", "Threepwood")
}

let name = pirateName()
let firstName = name.firstName
let lastName = name.lastName

3.1.5 Be wary of retain cycles when creating delegates/protocols for your classes; typically, these properties should be declared weak.

3.1.6 Be careful when calling self directly from an escaping closure as this can cause a retain cycle - use a capture list when this might be the case:

myFunctionWithEscapingClosure() { [weak self] (error) -> Void in
    // you can do this

    self?.doSomething()

    // or you can do this

    guard let strongSelf = self else {
        return
    }

    strongSelf.doSomething()
}

3.1.7 Don't use labeled breaks.

3.1.8 Don't place parentheses around control flow predicates.

// PREFERRED
if x == y {
    /* ... */
}

// NOT PREFERRED
if (x == y) {
    /* ... */
}
  • 3.1.9 Avoid writing out an enum type where possible - use shorthand.
// PREFERRED
imageView.setImageWithURL(url, type: .person)

// NOT PREFERRED
imageView.setImageWithURL(url, type: AsyncImageView.Type.person)
  • 3.1.10 Don’t use shorthand for class methods since it is generally more difficult to infer the context from class methods as opposed to enums.
// PREFERRED
imageView.backgroundColor = UIColor.white

// NOT PREFERRED
imageView.backgroundColor = .white

3.1.11 Prefer not writing self. unless it is required.

3.1.12 When writing methods, keep in mind whether the method is intended to be overridden or not. If not, mark it as final, though keep in mind that this will prevent the method from being overwritten for testing purposes. In general, final methods result in improved compilation times, so it is good to use this when applicable. Be particularly careful, however, when applying the final keyword in a library since it is non-trivial to change something to be non-final in a library as opposed to have changing something to be non-final in your local project.

3.1.13 When using a statement such as else, catch, etc. that follows a block, put this keyword on the same line as the block. Again, we are following the 1TBS style here. Example if/else and do/catch code is below.

if someBoolean {
    // do something
} else {
    // do something else
}

do {
    let fileContents = try readFile("filename.txt")
} catch {
    print(error)
}

3.1.14 Prefer static to class when declaring a function or property that is associated with a class as opposed to an instance of that class. Only use class if you specifically need the functionality of overriding that function or property in a subclass, though consider using a protocol to achieve this instead.

3.1.15 If you have a function that takes no arguments, has no side effects, and returns some object or value, prefer using a computed property instead.

3.2 Access Modifiers

  • 3.2.1 Write the access modifier keyword first if it is needed.
// PREFERRED
private static let myPrivateNumber: Int

// NOT PREFERRED
static private let myPrivateNumber: Int
  • 3.2.2 The access modifier keyword should not be on a line by itself - keep it inline with what it is describing.
// PREFERRED
open class Pirate {
    /* ... */
}

// NOT PREFERRED
open
class Pirate {
    /* ... */
}

3.2.3 In general, do not write the internal access modifier keyword since it is the default.

3.2.4 If a property needs to be accessed by unit tests, you will have to make it internal to use @testable import ModuleName. If a property should be private, but you declare it to be internal for the purposes of unit testing, make sure you add an appropriate bit of documentation commenting that explains this. You can make use of the - warning: markup syntax for clarity as shown below.

/**
 This property defines the pirate's name.
 - warning: Not `private` for `@testable`.
 */
let pirateName = "LeChuck"

3.2.5 Prefer private to fileprivate where possible.

3.2.6 When choosing between public and open, prefer open if you intend for something to be subclassable outside of a given module and public otherwise. Note that anything internal and above can be subclassed in tests by using @testable import, so this shouldn't be a reason to use open. In general, lean towards being a bit more liberal with using open when it comes to libraries, but a bit more conservative when it comes to modules in a codebase such as an app where it is easy to change things in multiple modules simultaneously.

3.3 Custom Operators

Prefer creating named functions to custom operators.

If you want to introduce a custom operator, make sure that you have a very good reason why you want to introduce a new operator into global scope as opposed to using some other construct.

You can override existing operators to support new types (especially ==). However, your new definitions must preserve the semantics of the operator. For example, == must always test equality and return a boolean.

3.4 Switch Statements and enums

3.4.1 When using a switch statement that has a finite set of possibilities (enum), do NOT include a default case. Instead, place unused cases at the bottom and use the break keyword to prevent execution.

3.4.2 Since switch cases in Swift break by default, do not include the break keyword if it is not needed.

3.4.3 The case statements should line up with the switch statement itself as per default Swift standards.

3.4.4 When defining a case that has an associated value, make sure that this value is appropriately labeled as opposed to just types (e.g. case hunger(hungerLevel: Int) instead of case hunger(Int)).

enum Problem {
    case attitude
    case hair
    case hunger(hungerLevel: Int)
}

func handleProblem(problem: Problem) {
    switch problem {
    case .attitude:
        print("At least I don't have a hair problem.")
    case .hair:
        print("Your barber didn't know when to stop.")
    case .hunger(let hungerLevel):
        print("The hunger level is \(hungerLevel).")
    }
}

3.4.5 Prefer lists of possibilities (e.g. case 1, 2, 3:) to using the fallthrough keyword where possible).

3.4.6 If you have a default case that shouldn't be reached, preferably throw an error (or handle it some other similar way such as asserting).

func handleDigit(_ digit: Int) throws {
    switch digit {
    case 0, 1, 2, 3, 4, 5, 6, 7, 8, 9:
        print("Yes, \(digit) is a digit!")
    default:
        throw Error(message: "The given number was not a digit.")
    }
}

3.5 Optionals

3.5.1 The only time you should be using implicitly unwrapped optionals is with @IBOutlets. In every other case, it is better to use a non-optional or regular optional property. Yes, there are cases in which you can probably "guarantee" that the property will never be nil when used, but it is better to be safe and consistent. Similarly, don't use force unwraps.

3.5.2 Don't use as! or try!.

3.5.3 If you don't plan on actually using the value stored in an optional, but need to determine whether or not this value is nil, explicitly check this value against nil as opposed to using if let syntax.

// PREFERRED
if someOptional != nil {
    // do something
}

// NOT PREFERRED
if let _ = someOptional {
    // do something
}
  • 3.5.4 Don't use unowned. You can think of unowned as somewhat of an equivalent of a weak property that is implicitly unwrapped (though unowned has slight performance improvements on account of completely ignoring reference counting). Since we don't ever want to have implicit unwraps, we similarly don't want unowned properties.
// PREFERRED
weak var parentViewController: UIViewController?

// NOT PREFERRED
weak var parentViewController: UIViewController!
unowned var parentViewController: UIViewController
  • 3.5.5 When unwrapping optionals, use the same name for the unwrapped constant or variable where appropriate.
guard let myValue = myValue else {
    return
}
  • 3.5.6 Use XCTUnwrap instead of forced unwrapping in tests. ```swift func isEvenNumber(_ number: Int) -> Bool { return number % 2 == 0 }

// PREFERRED func testWithXCTUnwrap() throws { let number: Int? = functionThatReturnsOptionalNumber() XCTAssertTrue(isEvenNumber(try XCTUnwrap(number))) }

// NOT PREFERRED func testWithForcedUnwrap() { let number: Int? = functionThatReturnsOptionalNumber() XCTAssertTrue(isEvenNumber(number!)) // may crash the simulator }


### 3.6 Protocols

When implementing protocols, there are two ways of organizing your code:

1. Using `// MARK:` comments to separate your protocol implementation from the rest of your code
2. Using an extension outside your `class`/`struct` implementation code, but in the same source file

Keep in mind that when using an extension, however, the methods in the extension can't be overridden by a subclass, which can make testing difficult. If this is a common use case, it might be better to stick with method #1 for consistency. Otherwise, method #2 allows for cleaner separation of concerns.

Even when using method #2, add `// MARK:` statements anyway for easier readability in Xcode's method/property/class/etc. list UI.

### 3.7 Properties

* **3.7.1** If making a read-only, computed property, provide the getter without the `get {}` around it.

```swift
var computedProperty: String {
    if someBool {
        return "I'm a mighty pirate!"
    }
    return "I'm selling these fine leather jackets."
}
  • 3.7.2 When using get {}, set {}, willSet, and didSet, indent these blocks.
  • 3.7.3 Though you can create a custom name for the new or old value for willSet/didSet and set, use the standard newValue/oldValue identifiers that are provided by default.
var storedProperty: String = "I'm selling these fine leather jackets." {
    willSet {
        print("will set to \(newValue)")
    }
    didSet {
        print("did set from \(oldValue) to \(storedProperty)")
    }
}

var computedProperty: String  {
    get {
        if someBool {
            return "I'm a mighty pirate!"
        }
        return storedProperty
    }
    set {
        storedProperty = newValue
    }
}
  • 3.7.4 You can declare a singleton property as follows:
class PirateManager {
    static let shared = PirateManager()

    /* ... */
}

3.8 Closures

  • 3.8.1 If the types of the parameters are obvious, it is OK to omit the type name, but being explicit is also OK. Sometimes readability is enhanced by adding clarifying detail and sometimes by taking repetitive parts away - use your best judgment and be consistent.
// omitting the type
doSomethingWithClosure() { response in
    print(response)
}

// explicit type
doSomethingWithClosure() { response: NSURLResponse in
    print(response)
}

// using shorthand in a map statement
[1, 2, 3].flatMap { String($0) }
  • 3.8.2 If specifying a closure as a type, you don’t need to wrap it in parentheses unless it is required (e.g. if the type is optional or the closure is within another closure). Always wrap the arguments in the closure in a set of parentheses - use () to indicate no arguments and use Void to indicate that nothing is returned.
let completionBlock: (Bool) -> Void = { (success) in
    print("Success? \(success)")
}

let completionBlock: () -> Void = {
    print("Completed!")
}

let completionBlock: (() -> Void)? = nil

3.8.3 Keep parameter names on same line as the opening brace for closures when possible without too much horizontal overflow (i.e. ensure lines are less than 160 characters).

3.8.4 Use trailing closure syntax unless the meaning of the closure is not obvious without the parameter name (an example of this could be if a method has parameters for success and failure closures).

// trailing closure
doSomething(1.0) { (parameter1) in
    print("Parameter 1 is \(parameter1)")
}

// no trailing closure
doSomething(1.0, success: { (parameter1) in
    print("Success with \(parameter1)")
}, failure: { (parameter1) in
    print("Failure with \(parameter1)")
})

3.9 Arrays

3.9.1 In general, avoid accessing an array directly with subscripts. When possible, use accessors such as .first or .last, which are optional and won’t crash. Prefer using a for item in items syntax when possible as opposed to something like for i in 0 ..< items.count. If you need to access an array subscript directly, make sure to do proper bounds checking. You can use for (index, value) in items.enumerated() to get both the index and the value.

3.9.2 Never use the += or + operator to append/concatenate to arrays. Instead, use .append() or .append(contentsOf:) as these are far more performant (at least with respect to compilation) in Swift's current state. If you are declaring an array that is based on other arrays and want to keep it immutable, instead of let myNewArray = arr1 + arr2, use let myNewArray = [arr1, arr2].joined().

3.10 Error Handling

Suppose a function myFunction is supposed to return a String, however, at some point it can run into an error. A common approach is to have this function return an optional String? where we return nil if something went wrong.

Example:

func readFile(named filename: String) -> String? {
    guard let file = openFile(named: filename) else {
        return nil
    }

    let fileContents = file.read()
    file.close()
    return fileContents
}

func printSomeFile() {
    let filename = "somefile.txt"
    guard let fileContents = readFile(named: filename) else {
        print("Unable to open file \(filename).")
        return
    }
    print(fileContents)
}

Instead, we should be using Swift's try/catch behavior when it is appropriate to know the reason for the failure.

You can use a struct such as the following:

struct Error: Swift.Error {
    public let file: StaticString
    public let function: StaticString
    public let line: UInt
    public let message: String

    public init(message: String, file: StaticString = #file, function: StaticString = #function, line: UInt = #line) {
        self.file = file
        self.function = function
        self.line = line
        self.message = message
    }
}

Example usage:

func readFile(named filename: String) throws -> String {
    guard let file = openFile(named: filename) else {
        throw Error(message: "Unable to open file named \(filename).")
    }

    let fileContents = file.read()
    file.close()
    return fileContents
}

func printSomeFile() {
    do {
        let fileContents = try readFile(named: filename)
        print(fileContents)
    } catch {
        print(error)
    }
}

There are some exceptions in which it does make sense to use an optional as opposed to error handling. When the result should semantically potentially be nil as opposed to something going wrong while retrieving the result, it makes sense to return an optional instead of using error handling.

In general, if a method can "fail", and the reason for the failure is not immediately obvious if using an optional return type, it probably makes sense for the method to throw an error.

3.11 Using guard Statements

  • 3.11.1 In general, we prefer to use an "early return" strategy where applicable as opposed to nesting code in if statements. Using guard statements for this use-case is often helpful and can improve the readability of the code.
// PREFERRED
func eatDoughnut(at index: Int) {
    guard index >= 0 && index < doughnuts.count else {
        // return early because the index is out of bounds
        return
    }

    let doughnut = doughnuts[index]
    eat(doughnut)
}

// NOT PREFERRED
func eatDoughnut(at index: Int) {
    if index >= 0 && index < doughnuts.count {
        let doughnut = doughnuts[index]
        eat(doughnut)
    }
}
  • 3.11.2 When unwrapping optionals, prefer guard statements as opposed to if statements to decrease the amount of nested indentation in your code.
// PREFERRED
guard let monkeyIsland = monkeyIsland else {
    return
}
bookVacation(on: monkeyIsland)
bragAboutVacation(at: monkeyIsland)

// NOT PREFERRED
if let monkeyIsland = monkeyIsland {
    bookVacation(on: monkeyIsland)
    bragAboutVacation(at: monkeyIsland)
}

// EVEN LESS PREFERRED
if monkeyIsland == nil {
    return
}
bookVacation(on: monkeyIsland!)
bragAboutVacation(at: monkeyIsland!)
  • 3.11.3 When deciding between using an if statement or a guard statement when unwrapping optionals is not involved, the most important thing to keep in mind is the readability of the code. There are many possible cases here, such as depending on two different booleans, a complicated logical statement involving multiple comparisons, etc., so in general, use your best judgement to write code that is readable and consistent. If you are unsure whether guard or if is more readable or they seem equally readable, prefer using guard.
// an `if` statement is readable here
if operationFailed {
    return
}

// a `guard` statement is readable here
guard isSuccessful else {
    return
}

// double negative logic like this can get hard to read - i.e. don't do this
guard !operationFailed else {
    return
}
  • 3.11.4 If choosing between two different states, it makes more sense to use an if statement as opposed to a guard statement.
// PREFERRED
if isFriendly {
    print("Hello, nice to meet you!")
} else {
    print("You have the manners of a beggar.")
}

// NOT PREFERRED
guard isFriendly else {
    print("You have the manners of a beggar.")
    return
}

print("Hello, nice to meet you!")
  • 3.11.5 You should also use guard only if a failure should result in exiting the current context. Below is an example in which it makes more sense to use two if statements instead of using two guards - we have two unrelated conditions that should not block one another.
if let monkeyIsland = monkeyIsland {
    bookVacation(onIsland: monkeyIsland)
}

if let woodchuck = woodchuck, canChuckWood(woodchuck) {
    woodchuck.chuckWood()
}
  • 3.11.6 Often, we can run into a situation in which we need to unwrap multiple optionals using guard statements. In general, combine unwraps into a single guard statement if handling the failure of each unwrap is identical (e.g. just a return, break, continue, throw, or some other @noescape).
// combined because we just return
guard let thingOne = thingOne,
    let thingTwo = thingTwo,
    let thingThree = thingThree else {
    return
}

// separate statements because we handle a specific error in each case
guard let thingOne = thingOne else {
    throw Error(message: "Unwrapping thingOne failed.")
}

guard let thingTwo = thingTwo else {
    throw Error(message: "Unwrapping thingTwo failed.")
}

guard let thingThree = thingThree else {
    throw Error(message: "Unwrapping thingThree failed.")
}
  • 3.11.7 Don’t use one-liners for guard statements.
// PREFERRED
guard let thingOne = thingOne else {
    return
}

// NOT PREFERRED
guard let thingOne = thingOne else { return }

4. Documentation/Comments

4.1 Documentation

If a function is more complicated than a simple O(1) operation, you should generally consider adding a doc comment for the function since there could be some information that the method signature does not make immediately obvious. If there are any quirks to the way that something was implemented, whether technically interesting, tricky, not obvious, etc., this should be documented. Documentation should be added for complex classes/structs/enums/protocols and properties. All public functions/classes/properties/constants/structs/enums/protocols/etc. should be documented as well (provided, again, that their signature/name does not make their meaning/functionality immediately obvious).

After writing a doc comment, you should option click the function/property/class/etc. to make sure that everything is formatted correctly.

Be sure to check out the full set of features available in Swift's comment markup described in Apple's Documentation.

Guidelines:

4.1.1 160 character column limit (like the rest of the code).

4.1.2 Even if the doc comment takes up one line, use block (/** */).

4.1.3 Do not prefix each additional line with a *.

4.1.4 Use the new - parameter syntax as opposed to the old :param: syntax (make sure to use lower case parameter and not Parameter). Option-click on a method you wrote to make sure the quick help looks correct.

class Human {
    /**
     This method feeds a certain food to a person.

     - parameter food: The food you want to be eaten.
     - parameter person: The person who should eat the food.
     - returns: True if the food was eaten by the person; false otherwise.
    */
    func feed(_ food: Food, to person: Human) -> Bool {
        // ...
    }
}

4.1.5 If you’re going to be documenting the parameters/returns/throws of a method, document all of them, even if some of the documentation ends up being somewhat repetitive (this is preferable to having the documentation look incomplete). Sometimes, if only a single parameter warrants documentation, it might be better to just mention it in the description instead.

4.1.6 For complicated classes, describe the usage of the class with some potential examples as seems appropriate. Remember that markdown syntax is valid in Swift's comment docs. Newlines, lists, etc. are therefore appropriate.

/**
 ## Feature Support

 This class does some awesome things. It supports:

 - Feature 1
 - Feature 2
 - Feature 3

 ## Examples

 Here is an example use case indented by four spaces because that indicates a
 code block:

     let myAwesomeThing = MyAwesomeClass()
     myAwesomeThing.makeMoney()

 ## Warnings

 There are some things you should be careful of:

 1. Thing one
 2. Thing two
 3. Thing three
 */
class MyAwesomeClass {
    /* ... */
}
  • 4.1.7 When mentioning code, use code ticks - `
/**
 This does something with a `UIViewController`, perchance.
 - warning: Make sure that `someValue` is `true` before running this function.
 */
func myFunction() {
    /* ... */
}
  • 4.1.8 When writing doc comments, prefer brevity where possible.

4.2 Other Commenting Guidelines

  • 4.2.1 Always leave a space after //.
  • 4.2.2 Always leave comments on their own line.
  • 4.2.3 When using // MARK: - whatever, leave a newline after the comment.
class Pirate {

    // MARK: - instance properties

    private let pirateName: String

    // MARK: - initialization

    init() {
        /* ... */
    }

}

Download Details:

Author: linkedin
Source Code: https://github.com/linkedin/swift-style-guide 
License: View license

#swift #style #guide #ios