带有switch语句的简单javascript

我正在学习javascript，我正在努力让我的案例语句发挥作用。这样做的想法是，在它将调用函数的形式中输入1到7之间的任何数字，它将向您提供一周中的某一天。默认值为“无效日”。这看起来很简单，但我认为我做得对，我感觉这是一个可变的问题

function DayOfTheWeek()

var 1 = DayOfTheWeek;
var 2 = DayOfTheWeek;
var 3 = DayOfTheWeek;
var 4 = DayOfTheWeek;
var 5 = DayOfTheWeek;
var 6 = DayOfTheWeek;
var 7 = DayOfTheWeek;


switch (DayOfTheWeek){
case '1':
alert ("It's Monday");
break;

case 2:
alert ("It's Tuesday");
break;

case 3:
alert ("It's Wednsday");
break;

case 4:
alert ("It's Thursday");
break;

case 5:
alert ("It's Friday");
break;

case 6:
alert ("It's Saturday");
break;

case 7:
alert ("It's Sunday");
break;

default:
alert ("Not a valid day");
break;
}

---

几乎所有的代码都是错误的

您忘记了定义函数后的{和函数末尾的}。您希望使用与函数同名的变量（似乎您希望这样做）

变量名不能以数字开头

你想要的可能是：

    function DayOfTheWeek(day) {
        switch(day){
            case 1:
                alert ("It's Monday");
            break;
            case 2:
                alert ("It's Tuesday");
            break;

            case 3:
                alert ("It's Wednsday");
            break;

            case 4:
                alert ("It's Thursday");
            break;

            case 5:
                alert ("It's Friday");
            break;

            case 6:
                alert ("It's Saturday");
            break;

            case 7:
                alert ("It's Sunday");
            break;

            default:
                alert ("Not a valid day");
            break;
        }
    }

---

变量不能以数字开头。JavaScript解析器还能如何区分数字和变量呢？

dayOfWeek（）

函数定义的其余部分在哪里，忽略了未使用（而且不可能）的数值变量……此外，您可能希望传递一个参数，该参数的输出日期为星期几。