Question

所以我一直在学习Java，我偶然发现了一个问题，有人能告诉我它有什么问题吗？

package com.company;
import java.util.Scanner;

public class Main {
    Scanner input = new Scanner(System.in);
    int total = 0;
    int grade;
    int average = 0;
    int counter = 0;

    while (counter>10) {
        grade = input.nextInt();
        total += grade;
        counter++;
    }
     average = total/10;
        System.out.print("avg is: "+ aveg);
}

Answer 1

 while (counter>10)    //  while(0>10) ---> while(false){//Not executed}

虽然条件不为真，因为count为零所以当body不执行时

代替

while (counter<10)

并且还将你的代码放在函数中，因为在java中没有任何东西，除了在函数外部完成的声明和初始化

import java.util.Scanner;

public class Main {

//only declaration and initialization outside methods

public static void main(String a[]){

    Scanner input = new Scanner(System.in);
    int total = 0;
    int grade;
    int average = 0;
    int counter = 0; 

    while (counter<10) {
        grade = input.nextInt();
        total += grade;
        counter++;
    }
        average = total/10;
        System.out.print("avg is: "+ average);
  }
}

Demo

Answer 2

同样在您的代码中，您甚至没有使用hasNextInt方法检查是否存在下一个int值。

你的while循环不起作用，因为你在counter>10开始时正在测试counter = 0，所以它甚至不会进入while循环

除了你的while循环问题，你应该像这样修改代码

package com.company;
import java.util.Scanner;

public class Main {
    Scanner input = new Scanner(System.in);
    int total = 0;
    int grade;
    int average = 0;
    int counter = 0;

    while (counter>10) {
      if(input.hasNextInt()){ 
             //this line is important , 
             //else code will throw an exception if no more input is found next
        grade = input.nextInt();
        total += grade;
        counter++;
      }
    }
     average = total/10;
        System.out.print("avg is: "+ aveg);
}

我的java代码有什么问题？（while循环）

2 个答案: