Java中的两个整数相加

Question

我试图对用户输入的两个数字求和。但它不起作用

这就是我所做的

import java.util.*;

public class EX2 {
  public static void main(String[] args) {
    int x;
    int y;

    Scanner x = new Scanner(System.in);
    x.nextInt();

    Scanner y = new Scanner(System.in);
    y.nextInt();

    int sum = x + y;

    System.out.println(x + " " + y);
    System.out.println(sum);
  }
}

错误代码是

Error:(12, 17) java: variable x is already defined in method main(java.lang.String[])
Error:(13, 10) java: int cannot be dereferenced

我错过了什么吗？

Answer 1

您重用了x 和y 变量名称（因此出现variable x is already defined in method main 错误），并且忘记将从Scanner 读取的ints 分配给x 和y 变量。

此外，无需创建两个Scanner 对象。

public static void main(String[] args){
    int x;
    int y;

    Scanner sc = new Scanner(System.in);
    x = sc.nextInt();
    y = sc.nextInt();

    int sum = x + y;

    System.out.println(x +" "+ y);
    System.out.println(sum);
}

Answer 2

您知道扫描仪和整数共享同一个名称吗？

 int x;
 Scanner x = new Scanner(System.in);

这在 java 中是无效的，请考虑为扫描仪使用更具描述性的名称

Answer 3

import java.util.Scanner; 

public class Output {
   public static void main(String[] args)
{

/*
Step 1. Declare Variables 
*/

int varX;
int varY;
int sum;

/*
Step 2. Create a Scanner to take in user input
*/

Scanner scan = new Scanner(System.in);

/*
Step 3. varX and varY will take in the next two integers the user enters
*/

varX = scan.nextInt();
varY = scan.nextInt();

sum = varX + varY;

/*
Step 4. Print out the two chosen integers and display the sum
*/

System.out.println(varX + " + " + varY + " equals " + sum);
System.out.println(sum);
}

}