Java之if选择结构及switch语句

import java.util.Scanner;

public class Demo1 {

    public static void main(String[] args) {
            Scanner scan = new Scanner(System.in);
            System.out.println("请输入分数：");
            int score = scan.nextInt();
            if(score<=100 && score>=90){
                System.out.println("A");
            }else if(score<=90 && score>=80){
                System.out.println("B");
            }else if(score<=80 && score>=70){
                System.out.println("c");
            }else if(score<=70 && score>=60){
                System.out.println("D");
            }else if(score<=60 && score >=0){
                System.out.println("不合格！");
            }else{
                System.out.println("你的输入不合法");
            }
            scan.close();
        }
       
    }

public class Demo1 {

    public static void main(String[] args) {
        //case穿透 //switch 匹配一个具体的值
        char grade = 'C';
        switch (grade){
            case 'A':
                System.out.println("优秀");
                //如果不加break，当case匹配成功后程序就会往下一直执行
                break;//可选
            case 'B':
                System.out.println("良好");
                break;//可选
            case 'C':
                System.out.println("及格");
                break;//可选
            case 'D':
                System.out.println("不及格");
                break;//可选
            default:
                System.out.println("再接再厉");
        }

    }

}