PHP chop() Function

What You’ll Learn

The chop() function strips characters from the end of a string. It is an alias of rtrim() and is handy for cleaning trailing spaces, tabs, or custom characters left over from user input or file reads.

Definition and Usage

In PHP, chop() removes characters from the right end of a string and returns the result as a new string. With no second argument, it strips standard whitespace characters. For example, chop("Hello, World! ") returns "Hello, World!".

📝 Syntax

The chop() function accepts one required and one optional parameter:

string chop(string $string, string $characters = " \t\n\r\0\x0B")

Parameters

• $string — the input string to trim from the right.
• $characters (optional) — a list of characters to remove from the end. If omitted, PHP strips whitespace: space, tab, newline, carriage return, NUL, and vertical tab.

Return Value

Returns a new string with trailing characters removed. The original $string is not modified.

Examples Gallery

Run these examples in any PHP 7+ environment. Each one shows a common pattern beginners encounter with chop().

<?php
$text    = "Hello, World!   ";
$trimmed = chop($text);

echo "Before: '$text'\n";
echo "After:  '$trimmed'\n";
?>

Before: 'Hello, World!   '
After:  'Hello, World!'

<?php
$text    = "   PHP is awesome   \t";
$trimmed = chop($text, " \t");

echo "Result: '$trimmed'\n";
?>

Result: '   PHP is awesome'

<?php
$filename = "report.pdf...";
$clean    = chop($filename, ".");

$path     = "/api/users///";
$normalized = chop($path, "/");

echo "Filename: $clean\n";
echo "Path:     $normalized\n";
?>

Filename: report.pdf
Path:     /api/users

<?php
$s = "  hello world  ";

echo "chop():  '" . chop($s) . "'\n";
echo "ltrim(): '" . ltrim($s) . "'\n";
echo "trim():  '" . trim($s) . "'\n";
echo "rtrim(): '" . rtrim($s) . "'\n";
?>

chop():  '  hello world'
ltrim(): 'hello world  '
trim():  'hello world'
rtrim(): '  hello world'

<?php
// Simulated POST data with trailing newline and spaces
$email = "user@example.com  \n";

$cleanEmail = chop($email);

echo "Raw:   '$email'\n";
echo "Clean: '$cleanEmail'\n";
echo "Valid: " . (filter_var($cleanEmail, FILTER_VALIDATE_EMAIL) ? "yes\n" : "no\n");
?>

Raw:   'user@example.com  
'
Clean: 'user@example.com'
Valid: yes

🚀 Common Use Cases

• Form input cleanup — remove trailing spaces or newlines from emails, usernames, or comments.
• File line processing — strip newline characters from lines read with fgets().
• URL/path normalization — remove trailing slashes from directory paths.
• CSV or log parsing — clean trailing delimiters or padding characters.
• Legacy code — recognize chop() as identical to rtrim() when reading older PHP projects.

📝 Notes

• chop() is an alias of rtrim()—they are 100% identical.
• Only the right end is trimmed. Leading characters are never removed.
• The charlist is a set of individual characters, not a word or substring to match.
• PHP removes all consecutive trailing matches, not just one character.
• For most new code, rtrim() is preferred because the name clearly means “right trim.”

💡 Best Practices