YiXu Zhang

YiXu Zhang


Vanilla JavaScript Code Snippets

A guide to vanilla JavaScript code snippets — with resources and lightweight libraries to help you solve a problem without a large overhead or third-party dependencies.

Every now and again we have to deal with legacy code, wading through dark and eerie sides of the code base, often with a vague, ambiguous and unsettling documentation — if any is provided at all. In such cases, refactoring the component seems inevitable.

Or perhaps you need to manage dates and arrays, or manipulate DOM — there is just no need to add an external dependency for a simple task of that kind, but we need to figure out the best way to do that. It’s always a good idea to explore lightweight vanilla JavaScript snippets as well — preferably the ones that don’t have any third-party dependencies. Fortunately, there is no shortage in tooling to do just that.

30 Seconds Of Code

30 Seconds of Code features a huge repository of short code snippets for JavaScript, including helpers for dealing with primitives, arrays and objects, as well as algorithms, DOM manipulation functions and Node.js utilities. You can also find plenty of small utilities for Python, React Hooks, React Components and Node.js. It also features useful JavaScript cheatsheets.

30 Seconds Of Code

30 Seconds of Code, with a huge repository of short code snippets and JavaScript cheatsheets.


HTML Dom provides over 120 bulletproof, plain JavaScript snippets for everything from toggling password visibility to creating resizable split views — all supported for modern browsers and IE11+.


120 bulletproof, plain JavaScript snippets, on HTML Dom.

Vanilla JavaScript Toolkit

Vanilla JavaScript Toolkit provides a growing collection of vanilla JavaScript methods, helper functions, plugins, boilerplates, polyfills, and learning resources. Also, Chris Ferdinandi runs a Vanilla JS Academy, with plenty of daily developer tips on Vanilla JS sent in his newsletter.

Vanilla JavaScript Toolkit

Meet Vanilla JavaScript toolkit, a growing collection of vanilla JavaScript methods and helper functions.

Migrating from jQuery to Vanilla JavaScript

If you still find yourself in the land of legacy systems running on jQuery, there is a number of resources that allow you to slowly move away from jQuery with more lightweight and standardized options. One of the excellent guides is Tobias Ahlin’s Cheat sheet for moving from jQuery to vanilla JavaScript, a practical reference guide with some of the most common jQuery patterns and their equivalents in JavaScript.

Vanilla JavaScript Toolkit

Meet a practical reference guide with common jQuery patterns and their native JavaScript equivalents.

There are also many other useful resources worth taking a look at:

  • PlainJS, You Might Not Need jQuery and You Don’t Need jQuery are great references for vanilla JavaScript snippets. The sites feature repositories of code snippets for everything from UI and inputs to media, navigation and visual effects (with use cases not just for jQuery, but pretty much any legacy code).
  • Learn Vanilla JS features books, courses, evergreen resources, communities, podcasts all around vanilla JS. A fantastic repository that’s worth keeping close.
  • JavaScript Framework Diet is Sebastian De Deyne’s ongoing series on common tasks, solved without JavaScript frameworks. You’ll learn about selecting element, event delegation, file structure, dropdowns and enter and leave transitions.

Micro-Libraries Under 5K

Micro.js is a curated repository of small JavaScript libraries and utilities, collected by Thomas Fuchs. All libraries are grouped, and are below 5k in size, doing one thing and one thing only — and doin it well.

Micro-Libraries Under 5K

Micro.js is a curated repository of small JavaScript libraries and utilities.


What is GEEK

Buddha Community

Vanilla JavaScript Code Snippets

Rahul Jangid


What is JavaScript - Stackfindover - Blog

Who invented JavaScript, how it works, as we have given information about Programming language in our previous article ( What is PHP ), but today we will talk about what is JavaScript, why JavaScript is used The Answers to all such questions and much other information about JavaScript, you are going to get here today. Hope this information will work for you.

Who invented JavaScript?

JavaScript language was invented by Brendan Eich in 1995. JavaScript is inspired by Java Programming Language. The first name of JavaScript was Mocha which was named by Marc Andreessen, Marc Andreessen is the founder of Netscape and in the same year Mocha was renamed LiveScript, and later in December 1995, it was renamed JavaScript which is still in trend.

What is JavaScript?

JavaScript is a client-side scripting language used with HTML (Hypertext Markup Language). JavaScript is an Interpreted / Oriented language called JS in programming language JavaScript code can be run on any normal web browser. To run the code of JavaScript, we have to enable JavaScript of Web Browser. But some web browsers already have JavaScript enabled.

Today almost all websites are using it as web technology, mind is that there is maximum scope in JavaScript in the coming time, so if you want to become a programmer, then you can be very beneficial to learn JavaScript.

JavaScript Hello World Program

In JavaScript, ‘document.write‘ is used to represent a string on a browser.

<script type="text/javascript">
	document.write("Hello World!");

How to comment JavaScript code?

  • For single line comment in JavaScript we have to use // (double slashes)
  • For multiple line comments we have to use / * – – * /
<script type="text/javascript">

//single line comment

/* document.write("Hello"); */


Advantages and Disadvantages of JavaScript

#javascript #javascript code #javascript hello world #what is javascript #who invented javascript

Tyrique  Littel

Tyrique Littel


Static Code Analysis: What It Is? How to Use It?

Static code analysis refers to the technique of approximating the runtime behavior of a program. In other words, it is the process of predicting the output of a program without actually executing it.

Lately, however, the term “Static Code Analysis” is more commonly used to refer to one of the applications of this technique rather than the technique itself — program comprehension — understanding the program and detecting issues in it (anything from syntax errors to type mismatches, performance hogs likely bugs, security loopholes, etc.). This is the usage we’d be referring to throughout this post.

“The refinement of techniques for the prompt discovery of error serves as well as any other as a hallmark of what we mean by science.”

  • J. Robert Oppenheimer


We cover a lot of ground in this post. The aim is to build an understanding of static code analysis and to equip you with the basic theory, and the right tools so that you can write analyzers on your own.

We start our journey with laying down the essential parts of the pipeline which a compiler follows to understand what a piece of code does. We learn where to tap points in this pipeline to plug in our analyzers and extract meaningful information. In the latter half, we get our feet wet, and write four such static analyzers, completely from scratch, in Python.

Note that although the ideas here are discussed in light of Python, static code analyzers across all programming languages are carved out along similar lines. We chose Python because of the availability of an easy to use ast module, and wide adoption of the language itself.

How does it all work?

Before a computer can finally “understand” and execute a piece of code, it goes through a series of complicated transformations:

static analysis workflow

As you can see in the diagram (go ahead, zoom it!), the static analyzers feed on the output of these stages. To be able to better understand the static analysis techniques, let’s look at each of these steps in some more detail:


The first thing that a compiler does when trying to understand a piece of code is to break it down into smaller chunks, also known as tokens. Tokens are akin to what words are in a language.

A token might consist of either a single character, like (, or literals (like integers, strings, e.g., 7Bob, etc.), or reserved keywords of that language (e.g, def in Python). Characters which do not contribute towards the semantics of a program, like trailing whitespace, comments, etc. are often discarded by the scanner.

Python provides the tokenize module in its standard library to let you play around with tokens:



import io


import tokenize



code = b"color = input('Enter your favourite color: ')"



for token in tokenize.tokenize(io.BytesIO(code).readline):





TokenInfo(type=62 (ENCODING),  string='utf-8')


TokenInfo(type=1  (NAME),      string='color')


TokenInfo(type=54 (OP),        string='=')


TokenInfo(type=1  (NAME),      string='input')


TokenInfo(type=54 (OP),        string='(')


TokenInfo(type=3  (STRING),    string="'Enter your favourite color: '")


TokenInfo(type=54 (OP),        string=')')


TokenInfo(type=4  (NEWLINE),   string='')


TokenInfo(type=0  (ENDMARKER), string='')

(Note that for the sake of readability, I’ve omitted a few columns from the result above — metadata like starting index, ending index, a copy of the line on which a token occurs, etc.)

#code quality #code review #static analysis #static code analysis #code analysis #static analysis tools #code review tips #static code analyzer #static code analysis tool #static analyzer

Giles  Goodwin

Giles Goodwin


4 Ways You Can Get Rid of Dirty Side Effects for Cleaner Code in JavaScript

According to an analysis, a developer creates 70 bugs per 1000 lines of code on average. As a result, he spends 75% of his time on debugging. So sad!

Bugs are born in many ways. Creating side effects is one of them.

Some people say side effects are evil, some say they’re not.

I’m in the first group. Side effects should be considered evil. And we should aim for side effects free code.

Here are 4ways you can use to achieve the goal.

1. use strict;

Just add use strict; to the beginning of your files. This special string will turn your code validation on and prevent you from using variables without declaring them first.

#functional-programming #javascript-tips #clean-code #coding #javascript-development #javascript

JavaScript Snippet - Capitalize Text with JavaScript

JavaScript has built-in methods like .toLowerCase() – to convert text to lower case – and .toUpperCase() – to convert text to upper case. However, there’s no built-in method to convert text to title case i.e. “How Are You”. However, we can combine .toUpperCase() with another method .charAt() to achieve this result.

#snippets #javascript snippet #js #javascript

Creating a Real-Time QR Code Scanner With Vanilla JavaScript — Part 1/2

Using JavaScripts Built-In Barcode Detection API

What we will be making?

In this article, I’m going to show you how to create a Real-time QR code scanner with JavaScript using no libraries, frameworks, packages or node.js just plain vanilla JavaScript that runs on the browser. You can implement this into any framework you prefer using such as React, Vue, Angular and more.

See what we are making

How is it going to work?

We will be using the Barcode Detection API in JavaScript to make this possible if you have a quick look through the MDN documentation you’ll see you are not just restricted to scanning QR codes.

Preview Of What We Are Creating

In this part of the article, we will be creating the scanning functionality and learning how to access the camera to detect barcodes & QR codes in realtime in the next part of this article we will be learning how to create the outline around the code we are detecting/scanning and creating a previously scanned section that uses custom web components and proxies.

This series will start quite basic and become more difficult towards the end having a good knowledge of JavaScript can help with understanding some parts of these articles as proxies and web components can be hard to wrap your head around at first.

All the code is on my GitHub you may want to reference it for CSS if you want to make a carbon copy of this project I will be going over some of the CSS that makes the outlines around the barcodes possible but that’s about it for CSS as this is more focused on the JavaScript than the styling of the page.

#qr-code #programming #javascript #vanilla-javascript