PHP RFC: Multibyte for ucfirst, lcfirst functions, mb_ucfirst mb_lcfirst

• Version: 0.1
• Date: 2024-01-16
• Author: Author: Yuya Hamada(https://github.com/youkidearitai), youkidearitai@gmail.com
• Status: Draft
• First Published at: http://wiki.php.net/rfc/mb_ucfirst

PHP does not have a multibyte equivalent of ucfirst, lcfirst functions. It is possible to get close enough behavior below:

function mb_ucfirst(string $str, ?string $encoding = null): string
{
    return mb_strtoupper(mb_substr($str, 0, 1, $encoding), $encoding) . mb_substr($str, 1, null, $encoding);
}

function mb_lcfirst(string $str, ?string $encoding = null): string
{
    return mb_strtolower(mb_substr($str, 0, 1, $encoding), $encoding) . mb_substr($str, 1, null, $encoding);
}

However adding a pre-built functions to do this will implobe the readability and clarify of PHP code. And it will standardize how it is done as it can be tricky.

Add mb_ucfirst function, mb_lcfirst function.

function mb_ucfirst(string $string, ?string $encoding = null): string

function mb_lcfirst(string $string, ?string $encoding = null): string

According to research about Unicode, some (natural) lanugage doesn't may expected behavior, please deal with it in userland if any wrong. Because (natural) languages is a lot of exists, it is difficult to deal in mbstring.

This could break a function existing in userland with the same name.

next PHP 8.x

To SAPIs Will add the aforementioned functions to all PHP environments.

Adds mb_ucfirst(), mb_lcfirst() to the mbstring extension.

No effect.

No new constants.

No changed php.ini settings.

https://github.com/php/php-src/issues/13075

This section details areas where the feature might be improved in future, but that are not currently proposed in this RFC.

https://github.com/php/php-src/pull/13161

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