PHP metaphone() Function

Last Updated : 11 Jul, 2025

The metaphone() function is a built-in function in PHP and is used to calculate the metaphone key of a given string. The Metaphone key is a phonetic algorithm for indexing of words by their pronunciation. It uses the larger set of rules for English pronunciation.

Syntax:

string metaphone ( $str, $key )

Parameters: This function accepts two parameters as mentioned above and described below:

$str: It is Required parameter which represents the string to find the Metaphone key.
$key: It is an optional parameter which specified for Maximum length of the metaphone key.

Return Value: It returns the metaphone key as a string, and return FALSE in failure. Examples:

Input: $str = "Contribute Article on GeeksforGeeks"
Output: KNTRBTRTKLNJKSFRJKS

Input: $str = "Contribute Article on GeeksforGeeks"  $key = 5
Output: KNTRB

Below programs illustrate the metaphone() function in PHP.

Program 1:

php

<?php
$str1 = "Contribute Article on GeeksforGeeks";
echo metaphone($str1) . "\n";

$str2 = "A computer science portal";
echo metaphone($str2);
?>

Output:

KNTRBTRTKLNJKSFRJKS
AKMPTRSNSPRTL

Program 2:

php

<?php
$str1 = "Contribute Article on GeeksforGeeks";
echo metaphone($str1, 6) . "\n";

$str2 = "A computer science portal";
echo metaphone($str2, 5);
?>