How to convert PascalCase to pascal_case?

Question

If I had:

$string = \"PascalCase\";

I need

\"pascal_case\"

Does PHP offer a function for this purpose?

Answer 1

$str = 'FooBarBaz';

return strtolower(preg_replace('~(?<=\\w)([A-Z])~', '_$1', $str)); // foo_bar_baz