How To Extract Extension From Filename Using PHP?

Teams applying “How To Extract Extension From Filename Using PHP?” in a production project can use practical job hopping to record implementation, review and debugging time, then compare that effort with tests and shipped functionality instead of treating activity as performance by itself.

Before copying the example into a live application, confirm version-specific behaviour with the PHP project and test it against the project’s actual database and runtime.

Hi Dev,

There are a few different ways to extract the extension from a filename with PHP.

This example is base to php different ways to extract the extension from a filename with PHP.

This is a simple way and easy short code example.

So let's start example following step.

Example : 1

Using pathinfo(): The pathinfo() is a function that returns information about a file. If the second optional parameter is omitted, an associative array containing dirname, basename, extension, and the filename will be returned. If the second parameter is true, it will return specific data.

<?php
    $file_name = 'nicesnippets.pdf';
    $extension = pathinfo($file_name, PATHINFO_EXTENSION);
    echo $extension;
?>

Output:

pdf

Example : 2

Explode the file variable and get the last array element to be the file extension. The PHP end() function is used to get the last element of the array.

<?php
    $file_name = 'index.html';
    $temp= explode('.',$file_name);
    $extension = end($temp);
    echo $extension;
?>

Output:

html

Example : 3

Using substr() and strrchr() functions:

substr(): A part of the string is returned.

strrchr(): The last occurrence of a string inside another string is determined.

<?php
    $file_name = 'index.html';
    $extension = substr(strrchr($file_name, '.'), 1);
    echo $extension;
?>

Output:

html

Example : 4

Using strrpos() to find the last occurrence position of a ‘.’ in a filename and enhance the file position by 1 to explode string (.)

<?php
    $file_name = 'index.html';
    $extension = substr($file_name, strrpos($file_name, '.') + 1);
    echo $extension;
?>

Output:

html

Example : 5

Using regular expressions like replace and search. The first parameter of the preg_replace() function is the search pattern, the second parameter $1 is a reference to whatever matches the first (.*), and the third parameter is the file name.

<?php
    $file_name = 'nicesnippets.jpg';
    $extension = preg_replace('/^.*\.([^.]+)$/D', '$1', $file_name);
    echo $extension;
?>

Output:

jpg

I hope it can be useful....