How to check a string contains substring in php?

The function will check a string contains substring, the string to be checked may contain underscores.

1. Code:

  <?php 
	function checkContainsSubstringWithUnderscore($str, $substr){
		$hayStack = strtolower((string)$str);
		$needle = strtolower((string)$substr);
		$pos = strpos($str,$substr);
		$matchItemName = true;
		$isPass1 = true;
		$isPass2 = true;
		if($pos === false){
			$isPass1 = false;
		}
		$needle = str_replace("_"," ",$substr);
		$pos = strpos($str,$substr);
		if($pos === false){
			$isPass2 = false;
		}
		if(!$isPass1 && !$isPass2){
			$matchItemName = false;
		}
		return $matchItemName;
	}
        $str = "Soltuts.com is providing PHP tutorials";
	$substr = "Soltuts.com";
	var_dump(checkContainsSubstringWithUnderscore($str, $substr));	
    ?>

2. Example:

Input:

$str = "Soltuts.com is providing PHP tutorials";
$substr = "Soltuts.com";
$substr1 = "PHP_tutorials";
checkContainsSubstringWithUnderscore($str, $substr);
checkContainsSubstringWithUnderscore($str, $substr1);

Output:

bool(true)  
bool(true)