How to remove all zeros from the beginning of a string?

Question

PHP

Can you please tell me a regular expression to remove all zeros from the beginning of a string.
The number of zeros can be different (0012345, 0000012345, 000000000000000012345).

Answer 1

ltrim($str, '0')

Answer 2

Catch another option in the piggy bank:
(string) (int) $str;