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

Nested loops

Sometimes it can be necessary to use a loop inside a loop. A loop inside a loop is called a nested loop. Often it is not the best solution to the problem. It could even be a sign of poorly written code (sometimes called "code smell" among programmers), but every now and then it is a perfectly fine solution to a problem.

Here is what it would look like for while loops:

while (condition 1) {
  // code that gets executed as long as condition 1 is true
  // this loop depends on condition 1 being true
    while (condition 2) {
      // code that gets executed as long as condition 2 is true
    }
}

Nesting can also be used with for loops, or with a combination of both for and while, or even with all kinds of loops; they can go several levels deep.

An example in which we might use nested loops would be when we want to create an array of arrays. With the outer loop, we create the top-level array, and with the inner loop we add the values to the array...