PHP rtrim() Function: Removing Trailing Characters

rtrim() removes trailing whitespace characters (or other specified characters) from a string and returns the modified string.

The function accepts two parameters: string $str, the input string, and an optional string $character_mask that lists characters to be stripped; ranges can be defined with ...

If $character_mask is omitted, rtrim() removes the following characters by default: space (ASCII 32), tab (\t), newline (\n), carriage return (\r), NUL byte (\0), and vertical tab (\x0B).

Parameters str: The input string. character_mask: Optional list or range of characters to remove.

Return value

Returns the string after the specified characters have been stripped from its end.

Example usage

<?php
$text = "\t\tThese are a few words :) ...  ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";
var_dump($text, $binary, $hello);
$trimmed = rtrim($text);
var_dump($trimmed);
$trimmed = rtrim($text, " \t.");
var_dump($trimmed);
$clean = rtrim($binary, "\x00..\x1F");
var_dump($clean);
?>

The first var_dump shows the original variables, the second displays the result of rtrim($text) (removing default whitespace), the third shows removal of spaces, tabs, and periods, and the final dump demonstrates stripping control characters from a binary string.