Javascript Concepts: 1St Edition

By Mohammed Ashequr Rahman

This book is about understanding the concepts of JavaScript as a language and then applying these concepts to develop dynamic Web pages using JavaScript.

The first objective of this book is to make it easy to write JavaScript solutions to a programming problem. Debugging and correcting your code quickly also becomes very easy at that point.

The second objective is to enable you to apply these concepts on another challenging language, like Java, C#.

Finally, I can promise you that by the time you finish reading this book and practice the exercises, you will become a master of JavaScript and ready to take on the next JavaScript challenge.

• Language: English
• Publisher: AuthorHouse
• Release date: Jun 16, 2017
• ISBN: 9781524694463

Mohammed Ashequr Rahman

Mohammed Ashequr Rahman is an adjunct professor at New York University’s (NYU) for over 20 years. During the last 20 years he has taught various courses at NYU including Java, Advanced Java, Java Web Services, JavaScript and Visual Basic. He has published a book titled “JavaScript Concepts” that is being used as a text book for JavaScript classes. He has recently started teaching at Hofstra University. Mohammed has a MS in Computer Science from NYU and has been working in IT field for the last 30 years. He also has an MBA with a Finance major from SUNY, Stony Brook. Mohammed is certified Project Management Professional and Oracle certified Java programmer.

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© 2017 Mohammed Ashequr Rahman. All rights reserved.

No part of this book may be reproduced, stored in a retrieval system, or transmitted by any means without the written permission of the author.

Published by AuthorHouse 06/16/2017

ISBN: 978-1-5246-9445-6 (sc)

ISBN: 978-1-5246-9446-3 (e)

Any people depicted in stock imagery provided by Thinkstock are models,

and such images are being used for illustrative purposes only.

Certain stock imagery © Thinkstock.

Because of the dynamic nature of the Internet, any web addresses or links contained in this book may have changed since publication and may no longer be valid. The views expressed in this work are solely those of the author and do not necessarily reflect the views of the publisher, and the publisher hereby disclaims any responsibility for them.

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Contents

Section A – JavaScript Language

Chapter 1

Data Types in JavaScript

JavaScript and Browser Console

Variable Naming Convention

Arithmetic Operations

Commenting your code

Conditional Operation

Truthy and Falsy in JavaScript

Undefined on the Console

Embedding JavaScript in an HTML file

JavaScript Debugging

Loops

Chapter 2

What is a Function?

Default values of parameters

Invalid parameters

Converting a no parameter function into an unlimited parameter function

Variable Scope in JavaScript – Global vs. Local Variables

Global Disaster in JavaScript

Parameter Passing, Pass By Value

Function as Variable

Chapter 3

Arrays

For-in loop

Arrays Functions (methods)

Function as Parameter and forEach loop

Function as Parameter and Number Sorting In Array

What is object?

Object and []

Object and for-in loop

Methods

Object containing Object

Constructor

Methods on Prototype of Constructor

instanceof Operator

Parameter Passing, Pass By Reference

Array as Object

Function as Object:

String, Number, Boolean Object

Regular Expression

Section B – JavaScript and HTML

Chapter 4

What is HTML?

What is HTTP?

Fiddler Tool

Tomcat

Abyss

What is DOM?

HTML DOM and JavaScript

Modifying DOM impacts the HTML page

Chapter 5

Getting to Elements in DOM using JavaScript

HTML tags – , type text,password and button

and tag

Programmatic

submission

Checkbox and Validation

Radio Button and Validation

Dropdown and Validation

List and Validation

TextArea

Chapter 6

Getting to know Events

Event Handling Options

Cancelling Event – preventDefault()

DOMContentLoaded Event

Event Bubbling

this vs Event.target

Event Capturing

Canceling the Bubbling

Use of Bubbling

Creating Tabs on a page

Chapter 7

XML Parsing and Serialization

JSON (JavaScript Object Notation)

AJAX (Asynchronous JavaScript and XML)

AJAX and XML

AJAX and JSON

Chapter 8

Slideshow

Appending Nodes in DOM

Inserting Before

Deletion

Dynamic Delete Button

Dynamic Table

Dynamic Photo Gallery

Section C - JQuery

Chapter 9

What is JQuery?

Why JQuery?

How to get JQuery?

How to include any JavaScript file in your html?

How do you include JQuery JavaScript file in your html?

What function in JQuery’s .js file can I call?

How to use JQuery?

JQuery Selectors

JQuery Append

JQuery inserting innerHTML

JQuery adding and removing event handler

JQuery AJAX

$.each() function in JQuery

Preface

This book is about understanding of the concepts of JavaScript as a language and then applying these concepts to develop dynamic web pages using JavaScript.

The first objective of this this book is to make it easy to write JavaScript solutions to a programming problem. Debugging and correcting your code quickly becomes also very easy at that point.

The second objective is to enable you to apply these concepts on another challenging language like Java, C#.

Finally, I can promise you that by the time you finish reading this book and practice the exercises, you will become a master of JavaScript and ready to take on the next JavaScript challenge.

About the Author

Mohammed Ashequr Rahman is an adjunct professor at New York University’s (NYU) for over 20 years. During the last 20 years he has taught various courses at NYU including JavaScript, Java and Visual Basic.

He has recently started teaching JavaScript at Hofstra University.

Mohammed has a MS in Computer Science from NYU and has been working in IT field for the last 29 years.

He is also finishing up his MBA with a Finance major at SUNY, Stony Brook.

Mohammed is certified PMP and Oracle certified Java programmer.

Introduction

This book is broken down into 3 fundamental sections. In the first section, we will learn JavaScript as a language. In the second section, we will learn how to use JavaScript with the web pages to generate dynamic content. In the third section, we will learn how to use JQuery, the most popular JavaScript libraries.

You can download all the examples in the book from the following url:

https://drive.google.com/file/d/0BzE52XmaCfzuTjBNd1RQNTYzd1k/view?usp=sharing

Section A – JavaScript Language

Chapter 1

Why JavaScript?

JavaScript is the language of the web. Even a modest web application has tons of JavaScript in it.

JavaScript is simple, easy to learn. It lets you make tons of mistakes and easily recover from them. It’s awesome!

JavaScript Interpreter

We generally write a computer program using a high-level language like JavaScript. A high-level language is one which is understandable by us humans. It contains words and phrases from the English language. But a computer does not understand English. It only understands program written in 0’s and 1’s in binary, called the machine code. So, a program written in English like high level language needs to be translated to machine code.

A program written in high-level language is called a source code. We need to convert the source code into machine code and this is accomplished by either a) compilers or b) interpreters.

Hence, a compiler or an interpreter is something that converts source code written in high-level language into machine code understood by the computer.

Language like C, C++, and Pascal uses compiler to do the job. A compiler converts all the source code to machine code at once and hides the source code as intellectual property of the company. Hence users never get to see the source code. A compiler is like a person translating your written lecture from English to German.

JavaScript, on the other hand, uses Interpreter instead. An Interpreter converts source code to machine code one line at a time. An interpreter is like a person who translates your verbal lecture from English to German as you speak.

One side effect of using interpreter is that the source code is open to public. Your browser downloads the JavaScript source code and runs as Interpreter. Therefore, JavaScript source code is wide open to public. We can learn a lot from JavaScript written by other people.

JavaScript Editor

Download Sublime Text latest version. This is our JavaScript editor for now. We can write JavaScript Code here and then run them on Browser Console.

Browsers

Browser 1) Get Chrome Canary. This version of Chrome is updated almost daily. However, regular Chrome would work just fine. Click on the vertical bar with dots on the top right, select More Tools