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<str_replacestr_shuffle>
^String FunctionsLast updated: Mon, 26 Oct 2026

str_rot13

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

str_rot13 — Perform the rot13 transform on a string

Description

function str_rot13(string $string): string

Performs the ROT13 encoding on the string argument and returns the resulting string.

The ROT13 encoding simply shifts every letter by 13 places in the alphabet while leaving non-alpha characters untouched. Encoding and decoding are done by the same function, passing an encoded string as argument will return the original version.

Parameters

string

The input string.

Return Values

Returns the ROT13 version of the given string.

Examples

Example #1 str_rot13() example

<?php

echo str_rot13('PHP 4.3.0'); // CUC 4.3.0

?>


<str_replacestr_shuffle>
^String FunctionsLast updated: Mon, 26 Oct 2026