Javascript switch语句

<script>
    var d = 7; //变量
    switch(d){ //对哪个变量进行switch操作
        case 1: //冒号，后无大括号
            console.log('Monday');
            break;
        case 2:
            console.log('Tuesday');
            break;
        case 3:
            console.log('Wednesday');
            break;
        case 4:
            console.log('Thursday');
            break;
        case 5:
            console.log('Friday');
            break;
        case 6: //后无内容无break，则直接跳下步
        case 7:
        default : //默认
            console.log("Enjoy weenkend !");
            break;
    }
script>