Question

With substr() you can omit the third parameter to get the whole rest of the string:

substr('abcdefg', 2) // returns "cdefg"

You can’t do the same with mb_substr():

mb_substr('abcdefg', 2, null, 'UTF-8'); // returns empty string

I only found weird and ugly solutions.

• Setting a very high number as length:

  $a = mb_substr('abcdefg', 2, 9999999999, 'UTF-8');

• Calculating the number:

  $a = mb_substr('abcdefg', 2, mb_strlen('abcdefg', 'UTF-8') - 2, 'UTF-8');

• Omitting the charset parameter by using mb_internal_encoding():

  $temp = mb_internal_encoding(); // prevent action at a distance
mb_internal_encoding('UTF-8');
$a = mb_substr('abcdefg', 2);
mb_internal_encoding($temp);

Isn’t there a real solution?

Answer 1

Change log shows this as a bug fix in Version 5.4.8 (18-October-2012).

http://us.php.net/ChangeLog-5.php

Allow passing null as a default value to mb_substr() and mb_strcut().
Patch by Alexander Moskaliov via GitHub PR #133.

Here is a link to the pull request thread also: https://github.com/php/php-src/pull/133