PHP rtrim Function: Remove Trailing Characters or Whitespace

You deal with user input, file reads, or formatted strings. PHP needed a way to remove extra characters from the end of a string without touching the rest. That is where rtrim() came in.

Understand the rtrim Function in PHP

The rtrim() function removes characters from the end of a string. You can use it to clean up trailing spaces, tabs, newlines, or any set of characters you choose.

Here is the syntax:

rtrim( $string, $characters )

Parameters:

• $string — This is the input string you want to trim.
• $characters (optional) — This is a list of characters you want PHP to remove from the end. If you skip this, PHP uses a default set of whitespace characters.

It returns a new string with the chosen characters removed from the right side. It does not change the original string.

The rtrim() function has been part of PHP from the start. You can use it in every stable version, including:

• PHP 4
• PHP 5
• PHP 7
• PHP 8 (up to 8.3)

You do not need extensions, and it works the same across versions.

Here is a quick example:

$price = "199.99$$$";
$cleanPrice = rtrim($price, '$');

echo $cleanPrice; 

Output:

199.99

This removes all trailing dollar signs from the end of the string. It only trims the end, not the start or middle.

Default Behavior (Removing Whitespace) with PHP rtrim Function

When you call rtrim() with just one argument, it removes whitespace from the end of the string. This includes:

• Spaces
• Tabs (\t)
• Newlines (\n)
• Carriage returns (\r)
• Null bytes (\0)
• Vertical tabs (\v)

Here is a simple example:

$text = "hello world   ";
$cleaned = rtrim($text);
echo $cleaned;  

Output:

hello world

PHP leaves the text untouched except for the trailing spaces.

Use PHP rtrim Function with Custom Character Mask

You can pass a second argument to tell rtrim() what to remove. This argument is a character mask, not a full string. PHP treats each character in it as a single match.

Here is an example that trims dots and dashes:

$line = "file-name.txt....---";
$clean = rtrim($line, ".-");
echo $clean;

Output:

file-name.txt

You can remove letters, symbols, or any mix. PHP reads each character one by one from the right side and stops when the next character does not match the list.

Examples of rtrim() Function in PHP

Remove whitespace:

$value = "user input   ";
echo "[" . rtrim($value) . "]";

Output:

[user input]

This code removes extra spaces from the end of the string "user input ". It then shows the trimmed result inside square brackets: [user input].

Trim specific characters:

$url = "example.com///";
echo rtrim($url, "/");

Output:

example.com

This removes all slashes from the end of the string “example.com///”. The output becomes: example.com — only the end slashes go, not anything in the middle.

Clean file path endings:

$path = "/var/www/html///";
$fixed = rtrim($path, "/");
echo $fixed; // /var/www/html

Output:

/var/www/html

This trims all trailing slashes from the path string “/var/www/html///”. The result is “/var/www/html” — it keeps the rest of the path unchanged.

Trim trailing letters:

$data = "ReportAAA";
echo rtrim($data, "A");

Output:

Report

This removes all A characters from the end of the string “ReportAAA”. The output is “Report” — it stops once it hits a different character.

Wrapping Up

The rtrim() function gives you a simple way to clean up the right side of a string. It works with whitespace or any custom set of characters.

You can use it to fix file paths, URLs, or raw input. It does not change the original string and works in all PHP versions.

FAQs

$url = "example.com///";
echo rtrim($url, "/"); // "example.com"