PHP str_rot13() Function
Topic: PHP String ReferencePrev|Next
Description
The str_rot13() function performs the rot13 transform on a string.
The ROT13 (rotate by 13 places) encoding simply shifts every letter by 13 places in the alphabet. Non-alphabetical characters such as numbers, symbols, whitespace are left unchanged.
The following table summarizes the technical details of this function.
| Return Value: | Returns the ROT13 version of the given string. |
|---|---|
| Version: | PHP 4.2.0+ |
Syntax
The basic syntax of the str_rot13() function is given with:
The following example shows the str_rot13() function in action.
Example
Run this code »<?php
// Sample string
$str = "Apollo 13";
// Perform ROT13 encoding
echo str_rot13($str);
?>Note: Since there are 26 letters (2×13) in the English alphabet, ROT13 is its own inverse; so the same function can be used for encoding and decoding. Therefore, if you pass an encoded string as argument, the original string will be returned.
Parameters
The str_rot13() function accepts the following parameters.
| Parameter | Description |
|---|---|
| string | Required. Specifies the string to encode. |
More Examples
Here're some more examples showing how str_rot13() function actually works:
The following example demonstrates how to decode ROT13 encoded string using this function.
Example
Run this code »<?php
// Sample string
$str = "Ncbyyb 13";
// Perform ROT13 decoding
echo str_rot13($str);
?>
