remove a part at the end of string - last match only

Question

I'm using rtrim() to remove a part at the end of string, , US in my example:

<?php

$str = "Hello - world, c., US, US";

echo rtrim($str,", US");

?>

Output:

Hello - world, c.

It removed , US, US and i want to remove the last one only and the output should be Hello - world, c., US

How i can do that please?

Answer 1

rtrim() doesn't remove a specific string, it uses the string as a list of characters to remove at the end.

Use a regular expression replacement:

echo preg_replace('/, US$/', '', $str);

The $ anchors the match to the end of the string.

Answer 2

substr + strrpos approach:

$str = "Hello - world, c., US, US";
echo substr($str, 0, strrpos($str, ", US"));

The output:

Hello - world, c., US