': return $a > $b; case '>=': return $a >= $b; case '=': case '==': return $a == $b; case '===': return $a === $b; case '<=': return $a <= $b; case '<': return $a < $b; case '!=': case '<>': return $a != $b; case '!==': return $a !== $b; default: throw InvalidArgumentException::invalidOperator($operator); } } }