When working with PHP, you may need to uppercase the first Unicode character. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.
mb_ucfirst: PHP 8.4+ uppercases the first character and leaves the rest unchanged.
What Is mb_ucfirst in PHP?
Uppercase the first Unicode character. PHP 8.4+ uppercases the first character and leaves the rest unchanged.
Syntax:
mb_ucfirst(string $string, ?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+. Uppercasing the first code point is not a full title-case or sentence-case algorithm.
Example 1: Basic Usage
This example introduces the operation with a short and predictable input.
<?php
echo mb_ucfirst("hello world", "UTF-8");
The code focuses on the main operation. PHP 8.4+ uppercases the first character and leaves the rest unchanged.
Example 2: Another Case
Now compare a different input, locale, date, or option to see another part of the behavior.
<?php
echo mb_ucfirst("école", "UTF-8");
What changes? Requires PHP 8.4+. Uppercasing the first code point is not a full title-case or sentence-case algorithm.
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
$cities = ["paris", "london", "zürich"];
foreach ($cities as $city) {
echo mb_ucfirst($city, "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+ uppercases the first character and leaves the rest unchanged.
Important Behavior and Edge Cases
- Core behavior: PHP 8.4+ uppercases the first character and leaves the rest unchanged.
- Inputs and results: Requires PHP 8.4+. Uppercasing the first code point is not a full title-case or sentence-case algorithm.
- Alternatives: mb_convert_case() can convert a complete string to title case.
- 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_ucfirst | Uppercase the first unicode character. |
| Related PHP approach | mb_convert_case() can convert a complete string to title case. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Using an incorrect input or option | Requires PHP 8.4+. Uppercasing the first code point is not a full title-case or sentence-case algorithm. |
| Confusing this API with a related operation | mb_convert_case() can convert a complete string to title case. |
| 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_ucfirst helps you uppercase the first Unicode character.
- PHP 8.4+ uppercases the first character and leaves the rest unchanged.
- Requires PHP 8.4+. Uppercasing the first code point is not a full title-case or sentence-case algorithm.
Use mb_ucfirst when you need to uppercase the first Unicode character. 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.