如何从常量数组中获取类？

const CLASS_ARRAY = [
    'ClassA' => '/path/to/ClassA.php',
    'ClassB' => '/path/to/ClassB.php',
    'ClassC' => '/path/to/ClassC.php',
];

function getClassFromConstantArray($className) {
    if (array_key_exists($className, CLASS_ARRAY)) {
        require_once CLASS_ARRAY[$className];
        return new $className();
    } else {
        throw new Exception('Class not found in constant array.');
    }
}

$classA = getClassFromConstantArray('ClassA');
$classB = getClassFromConstantArray('ClassB');
$classC = getClassFromConstantArray('ClassC');