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

A version that doesn't use regex can be found in the Alchitect source:

decamelize($str, $glue='_')
{
    $counter  = 0;
    $uc_chars = '';
    $new_str  = array();
    $str_len  = strlen($str);

    for ($x=0; $x<$str_len; ++$x)
    {
        $ascii_val = ord($str[$x]);

        if ($ascii_val >= 65 && $ascii_val <= 90)
        {
            $uc_chars .= $str[$x];
        }
    }

    $tok = strtok($str, $uc_chars);

    while ($tok !== false)
    {
        $new_char  = chr(ord($uc_chars[$counter]) + 32);
        $new_str[] = $new_char . $tok;
        $tok       = strtok($uc_chars);

        ++$counter;
    }

    return implode($new_str, $glue);
}