Various Methods to Retrieve File Extension in PHP

This guide presents multiple ways to obtain a file's extension in PHP, offering concise code snippets and explanations for each approach.

Method 1:

$file = 'x.y.z.png';
echo substr(strrchr($file, '.'), 1);

Explanation: strrchr($file, '.') finds the last occurrence of a dot and returns the substring from that point; substr(..., 1) removes the leading dot.

Method 2:

$file = 'x.y.z.png';
echo substr($file, strrpos($file, '.') + 1);

Explanation: strrpos($file, '.') returns the position of the last dot, and substr extracts the characters after it.

Method 3:

$file = 'x.y.z.png';
$arr = explode('.', $file);
echo $arr[count($arr) - 1];

Explanation: explode splits the filename by dots into an array; the last element (index count($arr)-1) is the extension.

Method 4:

$file = 'x.y.z.png';
$arr = explode('.', $file);
echo end($arr); // end() returns the last array element

Explanation: Similar to Method 3, but uses end() to fetch the final array element directly.

Method 5:

$file = 'x.y.z.png';
echo strrev(explode('.', strrev($file))[0]);

Explanation: The filename is reversed, split by dot, the first part (original extension) is taken, then reversed back.

Method 6:

$file = 'x.y.z.png';
echo pathinfo($file)['extension'];

Explanation: pathinfo() returns an associative array with file path details; the 'extension' key holds the file extension.

Method 7:

$file = 'x.y.z.png';
echo pathinfo($file, PATHINFO_EXTENSION);

Explanation: Using the second argument of pathinfo(), PATHINFO_EXTENSION, directly returns the extension as a string.