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

This is one of shorter ways:

function camel_to_snake($input)
{
    return strtolower(ltrim(preg_replace('/([A-Z])/', '_\\1', $input), '_'));
}