java中的if介绍

if 定义形式

if(布尔运算值){源程序;}

else if(布尔运算值){源程序;}

else if(布尔运算值){源程序;}

else{程序}

package com.scanner.demo;

import java.util.Scanner;

public class IfDemo01 {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);//定义扫描仪
        System.out.println("请输入成绩:");
        int score = sc.nextInt();//接受成绩
        if (score>=90&&score<=100){
            System.out.println("A级");
        }else if (score>=80&&score<90){
            System.out.println("B级");
        }else if (score>=70&&score<80){
            System.out.println("C级");
        }else if (score>=60&&score<70){
            System.out.println("D级");
        }else if (score>=0&&score<60){
            System.out.println("不及格");
        }else {
            System.out.println("成绩不合法");
        }
        sc.close();//关闭资源,防止程序占用资源

    }
}