PHP strip_tags() Function

The strip_tags() function is an inbuilt function in PHP which is used to strips a string from HTML, and PHP tags. This function returns a string with all NULL bytes, HTML, and PHP tags stripped from a given $str.

Syntax:

string strip_tags( $str, $allowable_tags ) 

Parameters: This function accepts two parameters as mentioned above and described below: 

• $string: It is a required parameter that specifies the string to be check.
• $allow: It is an optional parameter that specifies allowable tags. These tags will not be removed.

Return Value: This function Returns the stripped string.

Exceptions:

• This function strip HTML comments and PHP tags. It can not be used this in $allow tags because this is already hardcoded.
• PHP 5.3.4 and later versions, ignored the self-closing XHTML tags
• strip_tags() does not validate the HTML.

Below programs illustrate the strip_tags() function in PHP: 

Program 1:

PHP

<?php

// PHP programme to illustrate
// strip_tags function without $allow parameter
echo strip_tags("Hello <b>GeeksforGeeks!</b>");
?>

Output:

Hello GeeksforGeeks!

Program 2:

PHP

<?php

// PHP programme to illustrate
// strip_tags function with $allow parameter

echo strip_tags("Hello <b><i>GeeksforGeeks!</i></b>", "<b>");
?>

Output

Hello <b>GeeksforGeeks!</b>

Reference: http://php.net/manual/en/function.strip-tags.php