【PHP】switch多条件写法

switch (true) {
            case ($costEgtHundredCount >= 6 && $userCostTotal >= 7500):
                $grade = 'blue';   # 蓝钻
                break;
            case ($costEgtHundredCount >= 4 && $userCostTotal >= 1500):
                $grade = 'green';  # 绿钻
                break;
            case ($costEgtHundredCount >= 2):
                $grade = 'red';    # 红钻
                break;
            default :
                $grade = 0;
        }