对我的代码进行测试并收到意外的答案

Question

我试图从下面的图像中获得测试3的预期结果。有人能以正确的方式指出我能够解决它吗？

import java.util.Scanner;
/**
 * Write a description of class TwoNumbers here.
 * @version 1.0
 */
public class TwoNumbers
{
    public static void main (String [] args)
    {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter two numbers (like this: 41.7 -22.5): ");
        Double number1 =  input.nextDouble();
        Double number2 = input.nextDouble();

        if(number1 == number2)
        {
            System.out.println("The first number is equal to the second");
        }

        else if(number1 > number2)
        {
            System.out.println("The First number is greater than second");
        }

        else
        {
            if(number1 < number2)
            System.out.println("The first number is less than second");
        }

}

}

Answer 1

您将double自动装箱到java.lang.Double s，这将是相同的，但可能不会使用完全相同的参考。

您应该使用原始double s：

double number1 = input.nextDouble();
double number2 = input.nextDouble();

或者，如果您使用java.lang.Double，请使用equals方法对其进行比较：，

if (number1.equals(number2))
{
    System.out.println("The first number is equal to the second");
}

Answer 2

如果你想比较两个非原始对象是否相等，你应该使用.equals()而不是==

if(number1.equals(number2)){
    System.out.println("The first number is equal to the second");
}