Book Image

Object-Oriented JavaScript - Third Edition

By : Stoyan STEFANOV, Antani
5 (1)
Book Image

Object-Oriented JavaScript - Third Edition

5 (1)
By: Stoyan STEFANOV, Antani

Overview of this book

JavaScript is an object-oriented programming language that is used for website development. Web pages developed today currently follow a paradigm that has three clearly distinguishable parts: content (HTML), presentation (CSS), and behavior (JavaScript). JavaScript is one important pillar in this paradigm, and is responsible for the running of the web pages. This book will take your JavaScript skills to a new level of sophistication and get you prepared for your journey through professional web development. Updated for ES6, this book covers everything you will need to unleash the power of object-oriented programming in JavaScript while building professional web applications. The book begins with the basics of object-oriented programming in JavaScript and then gradually progresses to cover functions, objects, and prototypes, and how these concepts can be used to make your programs cleaner, more maintainable, faster, and compatible with other programs/libraries. By the end of the book, you will have learned how to incorporate object-oriented programming in your web development workflow to build professional JavaScript applications.
Table of Contents (19 chapters)
15
B. Built-in Functions
17
D. Regular Expressions

Default parameters


Function parameters can be assigned default values. While calling the function, if a parameter is omitted, the default value assigned to the parameter is used:

    function render(fog_level=0, spark_level=100){ 
      console.log(`Fog Level: ${fog_level} and spark_level:
       ${spark_level}`) 
    } 
    render(10); //Fog Level: 10 and spark_level: 100 

In this example, we are omitting the spark_level parameter, and hence the default value assigned to the parameter is used. It is important to note that undefined is considered as an absence of parameter value; consider the following line of code, for example:

    render(undefined,10); //Fog Level: 0 and spark_level: 10 

While providing default values of parameters, it is possible to refer to other parameters as well:

    function t(fog_level=1, spark_level=fog_level){
      console.log(`Fog Level: ${fog_level} and spark_level: 
       ${spark_level}`) 
      //Fog Level: 10 and...