三元运算符

三元运算符多级使用,条件运算符是右结合的，也就是说，从右向左分组计算。

       例如:
         `a?b:c?d:e;`等价于`a?b:(c?d:e);`

问题：大于90成绩为A，60～89成绩为B，60以下为C

import java.util.Scanner;
public class Compare {
        public static void main(String []args){
            System.out.println("请输入这个同学的成绩");
            Scanner grade=new Scanner(System.in);
            int score=grade.nextInt();
            String number=score>100||score<0?"错误":
                          score>=90? ("这个同学的等级为A"):
                         (score>60&&score<90?"这个同学的等级为B":
                                 "这个同学的等级为C");
                 System.out.println(number);
 }
}

三种判断对比

三元运算符

class TestSanyuan{
   public static void main (String[] args){
//三元运算符号
       int gender = 1;
       char gText = gender == 1?'男':'女';
       System.out.println("三元运算符号结果："+gText);
   }
}

if语句

class Testif{
   public static void main (String[] args){
                   int gender = 1;
                   char genderText = '  ';
                   if(gender == 1){
                             genderText = '男';
                    }else{
                             genderText = '女';
                    }
                  System.out.println(genderText);
       }
}

switch语句

class Testif{
    public static void main (String[] args){
                   int gender = 1;
                   char genderText = '  ';
                   switch(gender){
                          case 1:
                                genderText = '男';
                                break;
                          case 2:
                                genderText = '女';
                                break;
                          default:
                                genderText = '人妖';
                                break;
                    }
                    System.out.println(genderText);
        }
}