remove substring from end of string

[Phear46]

I want to remove the last ' AND' from my string im using to build a mySQL query. I thought using rtrim was the way to go but either im wrong or im not using it correctly:

foreach ($dupArray as $k => $v) {
			$whereStr = $whereStr . "$k='$v' AND ";
		}
		
		rtrim($whereStr, "AND");
		echo $whereStr;

Anyone got any ideas? I swear ive seen this done else where but i cant find any examples

[Barand]

try

$str = "abcde AND ";

echo substr($str, 0, -4);    // --> 'abcde '

But if you store the WHERE conditions in an array then JOIN with " AND " you can avoid the problem

[Jessica]

Your string ends with " AND ". Not "AND".