Introduction to JavaScript : Syntax


Java script has a very simple and easy to learn syntax. You can write any JavaScript statement and execute it by placing it within the <script>... </script> tags in HTML documents. The <script> tag indicates to the browser that it has reached a point where all the text between these <script> tags are sets of statements that need to be executed. A simple example of Java Script syntax is as follows:

JavaScript code  

Let us illustrate the syntax of JavaScript with a simple program that prints “Hey there!”.   

            document.write("Hey there!") 

The output produced by this code will be

Hey there! 

White Spaces, Line Breaks and Semicolons  

JavaScript ignores irrelevant spaces, tabs, and new lines within a program. This allows free formatting and unrestricted levels of indentations to suit one's readability needs.

Simple statements in JavaScript and many other programming languages like java, C, etc. usually end with a semicolon. In JavaScript, you may omit semicolons if each instruction is placed on separate lines. For example, the following code explains the whole procedure described above.

    var x = 15
    var y = 25

When multiple statements are placed are on a single line, then semicolons are necessary to determine the end of the statements. 

<script language = "javascript" type = "text/javascript">
    var x = 15; var y = 25; var z = 30

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Introduction to JavaScript
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