When working with PHP, you may need to remove trailing whitespace or selected Unicode characters. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.
mb_rtrim: PHP 8.4+ strips trailing Unicode whitespace or selected characters.
What Is mb_rtrim in PHP?
Remove trailing whitespace or selected Unicode characters. PHP 8.4+ strips trailing Unicode whitespace or selected characters.
Syntax:
mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string
Parameters and return value: The signature above identifies the arguments and return type where the API has a single call. For topic guides, follow the sequence of calls in the examples. Always distinguish a returned value from an object or variable modified by reference.
Important: Requires PHP 8.4+. Character masks describe character sets rather than whole substrings.
Example 1: Basic Usage
This example introduces the operation with a short and predictable input.
<?php
echo "[" . mb_rtrim("Café ", null, "UTF-8") . "]";
The code focuses on the main operation. PHP 8.4+ strips trailing Unicode whitespace or selected characters.
Example 2: Another Case
Now compare a different input, locale, date, or option to see another part of the behavior.
<?php
echo mb_rtrim("Report...", ".", "UTF-8");
What changes? Requires PHP 8.4+. Character masks describe character sets rather than whole substrings.
Practical Example: Applying It in an Application
Use the following separate example as a starting point for a small application task. Check any extension or environment requirements below before running it.
<?php
$labels = ["Complete ", "Pending "];
foreach ($labels as $label) {
echo "[" . mb_rtrim($label, null, "UTF-8") . "]" . PHP_EOL;
}
The practical example demonstrates how to apply this operation to multiple values, a reusable task, or a validated input. PHP 8.4+ strips trailing Unicode whitespace or selected characters.
Important Behavior and Edge Cases
- Core behavior: PHP 8.4+ strips trailing Unicode whitespace or selected characters.
- Inputs and results: Requires PHP 8.4+. Character masks describe character sets rather than whole substrings.
- Alternatives: mb_trim() removes at both ends and mb_ltrim() at the beginning.
- Compatibility: mbstring is required for mb_* functions.
- Compatibility: This function was introduced in PHP 8.4.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
mb_rtrim | Remove trailing whitespace or selected unicode characters. |
| Related PHP approach | mb_trim() removes at both ends and mb_ltrim() at the beginning. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Using an incorrect input or option | Requires PHP 8.4+. Character masks describe character sets rather than whole substrings. |
| Confusing this API with a related operation | mb_trim() removes at both ends and mb_ltrim() at the beginning. |
| Assuming output is identical across environments | Check return values and required extensions or versions. mbstring is required for mb_* functions. This function was introduced in PHP 8.4. |
Key Takeaways
- mb_rtrim helps you remove trailing whitespace or selected Unicode characters.
- PHP 8.4+ strips trailing Unicode whitespace or selected characters.
- Requires PHP 8.4+. Character masks describe character sets rather than whole substrings.
Use mb_rtrim when you need to remove trailing whitespace or selected Unicode characters. Start with the first example, compare the second, and adapt the practical example to your inputs. Confirm the return value and environment requirements before adding it to production code.