java 写出switch语句的句法结构写一个关于switch的练习要求 写出代码注释

Switch语句的句法结构：

switch (expression) {
    case value1:
        // code to be executed if expression matches value1
        break;
    case value2:
        // code to be executed if expression matches value2
        break;
    case value3:
        // code to be executed if expression matches value3
        break;
    ...
    default:
        // code to be executed if expression doesn't match any case
}

关于Switch的练习：

import java.util.Scanner;

public class SwitchExercise {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("请输入一个数字：");
        int num = input.nextInt();
        switch (num) {
            case 1:
                System.out.println("星期一");
                break;
            case 2:
                System.out.println("星期二");
                break;
            case 3:
                System.out.println("星期三");
                break;
            case 4:
                System.out.println("星期四");
                break;
            case 5:
                System.out.println("星期五");
                break;
            case 6:
                System.out.println("星期六");
                break;
            case 7:
                System.out.println("星期日");
                break;
            default:
                System.out.println("输入错误");
        }
    }

}

这个练习要求用户输入一个数字，然后根据数字输出对应的星期几。如果输入的数字不在1-7之间，则输出“输入错误”