I know you’ve probably seen this topic a hundred times, and so have I, but this one has a different twist.  We already know that there are many ways to get the extension of a file, but which one is the fastest?  That’s what I’m going to address right now.

Contenders

In each of the code examples $file is set to c:\\xampplite\\htdocs\\index.php.

String-to-Array Method

<?php
$ext = end(explode('.', $file));
echo $ext; // outputs 'php'
?>

Sub-String Method

<?php
$ext = substr($file, strrpos($file, '.')+1);
echo $ext; // outputs 'php'
?>

Path Info Method

<?php
$ext = pathinfo($file, PATHINFO_EXTENSION);
echo $ext; // outputs 'php'
?>

Setup

To test each of the contenders I put together a script that timed the execution of 1,000,000 iterations of each command. If you would like the script you can download it here.

Results

Sub-String Method: 0.778156 seconds
String-to-Array Method: 1.889744 seconds
Path Info Method: 2.020036 seconds

Winner

Our winner? The Sub-String Method! Next time you reach for that line of code to get a file’s extension, go for gold, and choose the Sub-String Method.

<?php
$ext = substr($file, strrpos($file, '.')+1);
echo $ext; // outputs 'php'
?>