Remove a part of a string, but only when it is at the end of the string

Question

I need to remove a substring of a string, but only when it is at the END of the string.

for example, removing \'string\' at the end of the following strings :

Answer 1

IF you don't mind about performance AND the part of the string could be placed only at the end of string, THEN you can do this:

$string = "this is a test string";
$part = "string";
$string = implode( $part, array_slice( explode( $part, $string ), 0, -1 ) );
echo $string;
// OUTPUT: "this is a test "