Transform string into array in php

I'm sure this has been answered, but I have no idea how to research it. This is my string

[value1, value2, value3, ..., valueN]

and I'd like to know if there's a native function that transform it into a simple array

array('value1', 'value2', 'value3', ..., 'valueN');

Let it be clear that I'm looking to know if there's something already written that do it, that is, another approach other than strpos('[') and implode(',').