Question

我有一个简单的小问题，我需要从scanner.scan读取变量“age”，用户输入一个数字。它一直告诉我初始化它，但为了做到这一点，我需要为变量提供一个整数，我不想这样做。我怎么能解决这个问题？

import java.util.*;

import java.io.*; 

import java.util.Scanner;

public class Person

{

    public static void main(String[]args) 

    {

    int age;

    Scanner scan = new Scanner(System.in);

    System.out.println("Enter in your age.");

     if (age < 18) 

     {
         System.out.println("Youth is a beautiful thing.");
     } 

     else

     {
        System.out.println("Age is just a state of mind.");
     }


}
}

Answer 1

您必须阅读age。见下文。

import java.util.*;
import java.io.*; 
import java.util.Scanner;
public class Person
{
   public static void main(String[]args) 
   {
      int age;
      Scanner scan = new Scanner(System.in);

      System.out.println("Enter in your age.");
      age = scan.nextInt(); <---- **//This is what you are missing**

      if (age < 18) 
      {
         System.out.println("Youth is a beautiful thing.");
      } 

      else
      {
         System.out.println("Age is just a state of mind.");
      }
   }
}

Answer 2

System.out.println下的

（“输入你的年龄。”）;

    age = scan.nextInt();

Answer 3

您没有在任何地方阅读age。为此，请在初始化扫描后执行以下操作。

age = scan.nextInt();

Scanner.scan /初始化变量

3 个答案: