初学Java if选择语句

 1 import java.util.Scanner;
 2 
 3 public class SubtractionQuiz {
 4   public static void main(String[] agrs) {
 5     int number1 = (int)(Math.random() * 100);
 6     int number2 = (int)(Math.random() * 100);
 7         
 8     if (number1 < number2) {
 9         int temp = number1;
10         number1 = number2;
11         number2 = temp;
12     }
13     
14     System.out.print("What is " + number1 + " - " + number2 + "?");
15     Scanner input = new Scanner(System.in);
16     int answer = input.nextInt();
17     
18     if (number1 - number2 == answer) 
19         System.out.println("You are correct!");
20     else
21         System.out.println("You are wrong\n" + number1 + " - " + number2 + " should be " + (number1 - number2));
22     
23   }
24 }