php.js : is_null() function

is_null() function

The is_null () function is used to check whether a variable is null or not. The function returns true if a variable is null otherwise false.




is_null (var_name)


Name Description Required /
var_name The variable being checked Required Mixed*

*Mixed : Mixed indicates that a parameter may accept multiple (but not necessarily all) types.

Example of php.js is_null() function

In the following web document is_null() function test whether a variable is null or not.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>php.js : is_null() function example</title>
<script type="text/javascript" src="../../phpjs/variable/variable.min.js"> </script>
<h1 style="color: green">php.js : is_null() function example</h1>
<h3>Returns true if variable is null.</h3>
<hr />
<script type="text/javascript">
//This is done to make the following JavaScript code compatible to XHTML. <![CDATA[
var_name = true;
if (is_null(var_name))
document.write('Variable is null');
document.write('Variable is not null');

Output of the function:

Variable is not NULL 

View example of php.js is_null() function in browser

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