IF 语句

IF

package com.andy.base.Andy.operator.structure;

import java.util.Scanner;

public class IfDemo01 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入内容：");
       String s = scanner.nextLine();
       //equals:判断字符串是否相等
       if(s.equals("Hello")){
           System.out.println(s);
       }

        System.out.println("End");
        scanner.close();
    }
}

package com.andy.base.Andy.operator.structure;

import java.util.Scanner;

public class IfDemo02 {
    public static void main(String[] args) {
        //分数>60及格，小于60不及格
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入成绩：");
        int score = scanner.nextInt();

        if(score>60){
            System.out.println("及格");
        }else {
            System.out.println("不及格");
        }
        scanner.close();
    }
}

package com.andy.base.Andy.operator.structure;

import java.util.Scanner;

public class IfDemo03 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        /*
        if 语句至多有1个else语句，else 语句在所有的else if语句之后，
        if 语句可以有若干个 else if 语句，它们必须在else语句之前
        一旦其中一个else if 语句检测为 true，其他的else if 以及else 语句都跳过执行
         */
        System.out.println("请输入成绩：");
        int score = scanner.nextInt();

        if(score==100){
            System.out.println("恭喜满分");
        }else if (score<100 && score>=90){
            System.out.println("A级");
        }else if (score<90 && score>=80){
            System.out.println("B级");
        }else if (score<80 && score>=70){
            System.out.println("C级");
        }else if (score<70 && score>=60){
            System.out.println("D级");
        }else if (score<60 && score>=0){
            System.out.println("不及格");
        }else {
            System.out.println("成绩不合法");
        }
        scanner.close();
    }
}