张 小龙

1660310346

Golang Tutorial | Go User Input

The Scanf function scans text read from standard input, storing successive space-separated values into successive arguments as determined by the format. It returns the number of items successfully scanned.

package main

import "fmt"

func main() {

    var name string

    fmt.Print("Enter your name: ")
    fmt.Scanf("%s", &name)
    fmt.Println("Hello", name)
}

The example prompts the user to enter his name.

var name string

We define a string variable.

fmt.Scanf("%s", &name)

The entered value is stored into the name variable.

$ go run read_input.go
Enter your name: Robert
Hello Robert

We run the program and enter a name.
#go #golang 

What is GEEK

Buddha Community

Fannie Zemlak

Fannie Zemlak

1599854400

What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

张 小龙

1596440100

Anatomy of Conditional Statements and Loops in Go

Go provides if/else and switch conditional statements for code execution based on certain conditions. To execute some code over and over again, we have the for loop.

The if/else conditional statement

Go provides if, if-else, if-else if-else variants of if/else statement we are familiar with. It is used to check a condition, and execute some code when the condition is true or false.

The if condition

Simple use of if condition is demonstrated below. Unlike most of the programming languages, Go does not allow to wrap the condition inside parenthesis ().

#golang #programming #golang-tutorial #go-tutorial #go

Zander Herzog

Zander Herzog

1596793260

Secure HTTPS servers in Go

In this article, we are going to look at some of the basic APIs of the http package to create and initialize HTTPS servers in Go.

Image for post

(source: unsplash.com)

In the “Simple Hello World Server” lesson, we learned about net/http package, how to create routes and how [ServeMux](https://golang.org/pkg/net/http/#ServeMux) works. In the “Running multiple HTTP servers” lesson, we learned about [Server](https://golang.org/pkg/net/http/#Server) structure and how to run multiple HTTP servers concurrently.

In this lesson, we are going to create an HTTPS server using both Go’s standard server configuration and custom configuration (using [_Server_](https://golang.org/pkg/net/http/#Server) structure). But before this, we need to know what HTTPS really is?

HTTPS is a big topic of discussion in itself. Hence while writing this lesson, I published an article just on “How HTTPS works?”. I advise you to read this lesson first before continuing this article. In this article, I’ve also described the encryption paradigm and SSL certificates generation process.

If we recall the simplest HTTP server example from previous lessons, we only need http.``[ListenAndServe](https://golang.org/pkg/net/http/#ListenAndServe) function to start an HTTP server and http.``[HandleFunc](https://golang.org/pkg/net/http/#HandleFunc) to register a response handler for a particular endpoint.

Image for post

(https://play.golang.org/p/t3sOenOYAzS)

In the example above, when we run the command go run server.go , it will start an HTTP server on port 9000. By visiting http://localhost:9000 URL in a browser, you will be able to see a Hello World! message on the screen.

Image for post

(http://localhost:9000)

As we know, the nil argument to ListenAndServe() call invokes Go to use the [DefaultServeMux](https://golang.org/pkg/net/http/#DefaultServeMux) response multiplexer, which is the default instance of ServeMux structure provided globally by the Go. The HandleFunc() call adds a response handler for a specific route on the multiplexer instance.

The http.ListenAndServe() call uses the Go’s standard HTTP server configuration, however, in the previous lesson, how we can customize a server using [Server](https://golang.org/pkg/net/http/#Server) structure type.

To start an HTTPS server, all we need do is to call ServerAndListenTLS method with some configuration. Just like ServeAndListen method, this method is available on both the http package and the Server structure.

The http.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#ListenAndServeTLS) method uses the Go’s standard server implementation, however, both [Server](https://golang.org/pkg/net/http/#Server) instance and Server.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#Server.ListenAndServeTLS) method can be configured for our needs.

#go-programming-language #go #golang-tutorial #go-programming #golang

Neal Bode

Neal Bode

1599287850

Golang Array Example | Arrays in Go Tutorial Explained

Golang array is a fixed-size collection of items of the same type. The items of an array are stored sequentially and can be accessed using their index. If we want to declare an array in Go, a programmer specifies the type of the elements and the number of items required by an array.

Golang array example

Golang programming language provides a data structure called an** array**, which can store the fixed-size sequential collection of items of the same type.

The array is used to store the collection of data, but it is often more useful to think of the array as the collection of variables of the same type.

Instead of declaring individual variables, such as no1, no2, …, and no99, you declare one array variable such as numbers and use no[0], no[1], and …, no[99] to represent individual variables.

#golang #go #golang array #golang programming

Chesley Labadie

Chesley Labadie

1655304840

Go-web-workshop: Build Web Applications with Go on App Engine

Building Web Applications with Go

Welcome, gopher! You're not a gopher? Well, this workshop is for gophers, or people that use the Go programming language. But fear not if you've never written any Go before! I'd recommend you learn the basics for the language first with the Go tour.

This workshop has been run a couple of times with an instructor leading. The goal of this repo is to make it as easy as possible for individuals to follow the content by themselves. If you get stuck at any point, feel free to file issues asking questions.

Setting up your workspace

To go through this you will need the following:

  1. You have installed the Go Programming Language.
  2. You have set up a GOPATH by following the How to Write Go Code tutorial.
  3. You are somewhat familiar with the basics of Go. (The Go Tour is a pretty good place to start)
  4. You have a Google account and you have installed the Google Cloud SDK.

Contents

There's a lot to say about how to build web applications, in Go or any other language. But we only have one day so we won't try to cover too much. Instead we'll cover the basics, so you'll be able to explore other solutions and frameworks later.

The workshops is divided in eleven sections:

Resources

These are places where you can find more information for Go:

My favorite aspect of Go is its community, and you are now part of it too. Welcome!

As a newcomer to the Go community you might have questions or get blocked at some point. This is completely normal, and we're here to help you. Some of the places where gophers tend to hang out are:

Disclaimer

This is not an official Google product (experimental or otherwise), it is just code that happens to be owned by Google.

Author: Campoy
Source Code: https://github.com/campoy/go-web-workshop 
License: Apache-2.0 license

#go #golang #web