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

if and if else statements

We can make decisions in our code using if and if else statements. It is very much like this template:

if *some condition is true*, then *a certain action will happen*, else *another action will happen*

For example, if it is raining then, I will take my umbrella, else I will leave my umbrella at home. It is not that much different in code:

let rain = true;
if(rain){
  console.log("** Taking my umbrella when I need to go outside **");
} else {
  console.log("** I can leave my umbrella at home **");
}

In this case, the value of rain is true. And therefore, it will log to the console:

** Taking my umbrella when I need to go outside **

But let's first take a step back and look at the syntax. We start with the word "if." After this, we get something within parentheses. Whatever is between these parantheses will be translated to a Boolean. If the value of this Boolean is true, it will execute the block...