strlen() function is used to get string length.
Syntax : int strlen(string $string)
Returns the length of the given string on success, and 0 if the string is empty.

Example

<?php
	$firstString = 'this world is very beautiful';
	echo strlen($firstString) . "<br>"; 

	$secondString = 'php is easy';
	echo strlen($secondString); 
?>

Output :

28
11