我怎样才能做到这一点，如果用户输入 0，则输出行表示你不能在 java 中除以零

Question

我试图让 "a" 的用户输入不为 0，因为这会导致方程除以零，从而输出错误，我将能够使用 println 表示如果用户为 "a" 输入 0，则不能除以零这是我的代码，我不确定我做错了什么，我还是新手，只需要帮助：

import java.util.Scanner;

class a3main{

    public static void main(String[] args){

    Scanner keyboard = new Scanner(System.in);

    System.out.println("Enter the value of a");
    int a = keyboard.nextInt();

    System.out.println("Enter the value of b");
    int b = keyboard.nextInt();

    System.out.println("Enter the value of c");
    int c = keyboard.nextInt();

    double R1, R2, dis;

    dis = b * b - 4 * a * c; // This is the discriminant formula

    if(dis > 0 )
    {
        System.out.println("The roots are both real numbers and unequal");
        R1 = (-b + Math.sqrt(dis))/(2*a);

        System.out.println("The first root is: " + R1);

        R2 = (-b - Math.sqrt(dis))/(2*a);

        System.out.println("The second root is: " + R2);
        }
        else if(dis == 0)
        {   
         System.out.println("The roots are both equal and are equal");
         R1 = (-b + Math.sqrt(dis))/(2*a);
         System.out.println("The root is: " + R1);
                }    
         else if (a == 0)
    {
         System.out.println("You cannot divide by 0");
    }   
             else 
             {
       System.out.println("The roots are imaginary");
                     }
    }
}

Answer 1

您需要将 if(a == 0) 检查放在查看 dis 的检查之前。

我怎样才能做到这一点，如果用户输入 0，则输出行表示你不能在 java 中除以零

How can i make it so that if user inputs 0 a output line says that you cannot divide by zero in java

java

exception

quadratic-programming