case switch

##顺序结构

一步步往下执行的机构

## 选择结果

if 单选择结构

 

if 双选择结构

 

if多选择结构

```

import java.util.Scanner;
public class HelloWorld {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("请输入成绩");
        int score = scan.nextInt();
        if (score==100){
            System.out.println("A");
        }else if (score >= 60 && score <100){
            System.out.println("及格");
        }else if(score >= 0 && score <60){
            System.out.println("不及格");
        }else{
            System.out.println("输入不合法");
        }
        scan.close();
        }
    }
```

switch结构

 

 

```

public class HelloWorld {
    public static void main(String[] args) {

        int name = 30;
        int age = 20;
        switch (name-age) {
            case -10:
                System.out.println("Evans");
                break;
            case 10:
                System.out.println("even");
                break;
            default:
                System.out.println("what is it");
        }

        }
    }

```