PHP check string exist in string

The correct way to write the statement to check if string contains specific words is use strpos function.
Strpos is used to find the occurrence of one string inside other.

$str = 'She is going to public library';
//check if 'public' exist
if (strpos($str,'public') !== false)
{
	echo 'String public exist!';
}

Note that the use of !== false is deliberate; strpos returns either the offset at which the needle string begins in the haystack string, or the boolean false if the needle isn’t found. Since 0 is a valid offset and 0 is “falsey”, we can’t use simpler constructs like !strpos($str,’public’).

By Keenlio, November 17, 2014