PHP soundex() Function (original) (raw)

Last Updated : 11 Jul, 2025

The soundex() function is a built-in function in PHP and is used to calculate the Soundex key of a given string. The soundex key is a four character long alphanumeric string(starting with a letter) which represents the English pronunciation of the given string.

Syntax:

string soundex($str);

Parameters: This function accepts a single parameter $str which represents the string for which we want to find the Soundex key.

Return Value: It returns the soundex key as a string.

Below programs illustrate the soundex() function in PHP:

Program 1: In the below program, the soundex() function generates the soundex key of the string "geeksforgeeks".

php `

`

Output:

G216

Program 2: In the below program, we will see that two words having same pronunciation produce similar Soundex key.

php `

`

Output:

H600 H600

Reference: https://www.php.net/manual/en/function.soundex.php