<?php

xdebug_start_code_coverage();

function whatAmI($var) {
    if (is_string($var)) {
        return 'string';
    } elseif ($var instanceof \stdClass) {
        return '\stdClass';
    } elseif (is_scalar($var)) {
        return 'scalar';
    }
    return 'dunno!';
}

whatAmI(new \stdClass);
whatAmI(123);
whatAmI('string');
whatAmI(new DateTime());

var_dump(xdebug_get_code_coverage());