strrchr函数的反义词是什么？

Question

I want to remove all characters after last specific string. For this function I need opposite of strrchr function.

For example, I want to remove all characters after last "." from "Hello.World.pdf". But with strrchr function I can only remove "Hello.World" before "."!

I want something like this code:

<?php
echo strrchr("Hello.World.pdf" , "." , true);
?>

But this code isn't working!

Answer 1

If you are dealing with file names that can have various extensions and you would like to remove the extension, you can get the extension using pathinfo() and then use str_replace() to get rid of it:

$filename  = 'Hello.World.pdf';
$extension = pathinfo($filename, PATHINFO_EXTENSION);
$filename  = str_replace('.' . $extension, '', $filename);
echo $filename; //Hello.World

More info on pathinfo and str_replace