Question

所以我试图找到总和为素数的数字对。因此，用户将仅输入4个条目。我的问题是如何将输入方法中的变量num1 num2 num3 num4共享到另一个名为sumPair的方法。但我得到一个名为Required：Variable found：value

的错误

import java.util.Scanner;
public class PrimePair
{
    public static int  num1,  num2,  num3,  num4;    
    public static Scanner input = new Scanner(System.in);
    public static void main(String args[])
    {  
       input(num1,num2,num3,num4);         
    }        
    public static void input (int num1, int num2, int num3, int num4) 
    {
        num1 = 0;       
        {
            System.out.print("Enter a positive integer: ");        
            num1 = input.nextInt(); 
            if(num1 > 0)
            {
                System.out.println("Thank you.");                                
            }
            else
            while(num1==0 || num1 < 0)
            {
                System.out.print("Enter a positive integer: ");
                num1 = input.nextInt();
            }
        }
        num2 = 0;       
        {
            System.out.print("Enter a positive integer: ");        
            num2 = input.nextInt(); 
            if(num2 > 0)
            {
                System.out.println("Thank you.");                                
            }
            while(num2 == 0 || num2 < 0)
            {
                System.out.print("Enter a positive integer: ");
                num2 = input.nextInt();
            }
        }
        num3 = 0;       
        {
            System.out.print("Enter a positive integer: ");        
            num3 = input.nextInt(); 
            if(num3 > 0)
            {
                System.out.println("Thank you.");                                
            }
            while(num3 ==0 || num3 < 0)
            {
                System.out.print("Enter a positive integer: ");
                num3 = input.nextInt();
            }
        }
        num4 = 0;       
        {
            System.out.print("Enter a positive integer: ");        
            num4 = input.nextInt(); 
            if(num4 > 0)
            {
                System.out.println("Thank you.");                                
            }
            while(num4 == 0 || num4 < 0)
            {
                System.out.print("Enter a positive integer: ");
                num4 = input.nextInt();
            }
        }
    }    
    public static int sumPair(int num1, int num2)
    {
        num1 + num2 = sum1;
        return sum1;
}
}

Answer 1

您像任何其他方法一样调用void方法，只是它不返回值，因此您无法将结果分配给任何内容。在你的情况下：

public static void main(String args[])
{  
  int in = input();
  int[] comparisons = ...;
  findThePairs(comparisons, in);
}

阅读Java教程。

Answer 2

请注意，我将您的输入方法放在您的类中，您编写的每个代码都应该在类

中

import java.util.Scanner;
public class PrimePair
{
    public static Scanner input = new Scanner(System.in);
    public static void main(String args[])
    {  
        int in = input();
        ???????//calling the void method
        int exampleArray[] = {3,4,6};
        int someNumber = 1;
        findThePairs(exampleArray, someNumber);
        // For void you don't have return value so variable isn't needed as with other methods which return some value

    }         
    public static void findThePairs(int inputArray[], int inputNumber)
    {
        for (int i = 0; i < inputArray.length; i++)
        {
            for (int j = i+1; j < inputArray.length; j++)
            {
                if(inputArray[i]+inputArray[j] == inputNumber)
                {
                    System.out.println(inputArray[i]+" + "+inputArray[j]+" = "+inputNumber);
            }
        }
    }
    public static int input () 
    {
    int count = 0;
    int num = 0;
    while (count < 4)
    {
        System.out.print("Enter a positive integer: ");        
        num = input.nextInt(); 
        {
            if(num > 0)
            {
                System.out.println("Thank you.");     
                count++;
            }   

        }             

    }
    return num;
    }// End of input method
}// End of class

如何在另一个方法中使用变量num1，num2，num3，num4

2 个答案: