PHP | Find the number of sub-string occurrences

We are given two strings s1 and s2. We need to find the number of occurrences of s2 in s1.

Examples:

Input : $s1 = "geeksforgeeks", $s2 = "geeks"
Output : 2
Explanation : s2 appears 2 times in s1

Input : $s1 = "Hello Shubham. how are you?";   
        $s2 = "shubham"
Output : 0
Explanation : Note the first letter of s2 
is different from substrings present in s1.

The problem can be solved using PHP in built function for counting the number of occurrences of a substring in a given string.The in built function used for the given problem is:

• substr_count(): The substr_count() function counts the number of times a substring occurs in a string.
  Note: The substring is case-sensitive.

<?php
// PHP program to count number of times
// a s2 appears in s1.

$s1 = "geeksforgeeks";
$s2 = "geeks";

$res = substr_count($s1, $s2);

echo($res);
?>

Output :

2