Book Image

JavaScript from Beginner to Professional

By : Laurence Lars Svekis, Maaike van Putten, Codestars By Rob Percival
4 (5)
Book Image

JavaScript from Beginner to Professional

4 (5)
By: Laurence Lars Svekis, Maaike van Putten, Codestars By Rob Percival

Overview of this book

This book demonstrates the capabilities of JavaScript for web application development by combining theoretical learning with code exercises and fun projects that you can challenge yourself with. The guiding principle of the book is to show how straightforward JavaScript techniques can be used to make web apps ranging from dynamic websites to simple browser-based games. JavaScript from Beginner to Professional focuses on key programming concepts and Document Object Model manipulations that are used to solve common problems in professional web applications. These include data validation, manipulating the appearance of web pages, working with asynchronous and concurrent code. The book uses project-based learning to provide context for the theoretical components in a series of code examples that can be used as modules of an application, such as input validators, games, and simple animations. This will be supplemented with a brief crash course on HTML and CSS to illustrate how JavaScript components fit into a complete web application. As you learn the concepts, you can try them in your own editor or browser console to get a solid understanding of how they work and what they do. By the end of this JavaScript book, you will feel confident writing core JavaScript code and be equipped to progress to more advanced libraries, frameworks, and environments such as React, Angular, and Node.js.
Table of Contents (19 chapters)
16
Other Books You May Enjoy
17
Index

Changing the classes of an element

HTML elements can have classes, and as we have seen, we can select elements by the name of the class. As you may remember, classes are used a lot for giving elements a certain layout using CSS.

With JavaScript, we can change the classes of HTML elements, and this might trigger a certain layout that is associated with that class in CSS. We are going to have a look at adding classes, removing classes, and toggling classes.

Adding classes to elements

This might sound a bit vague, so let's have a look at an example where we are going to add a class to an element, which in this case will add a layout and make the element disappear.

<!DOCTYPE html>
<html>
  <body>
    <script>
       function disappear(){
         document.getElementById("shape").classList.add("hide");
       }
    </script>
    <style>
      .hide {
        display: none;
      }
      .square {
        height...