java第五次上机

Question

设计一个Java程序，从键盘输入两个数，进行减法运算，当输入串含有非数字时，通过异常处理机制使程序正常运行

Code

import java.util.Scanner;
​
public class test {
​
    private static Scanner sc;
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        test2();
    }
    public static void test2() {
        System.out.println("输入一个数字哇");
        sc = new Scanner(System.in);
        int x, y;
        try {
            x = sc.nextInt();
            y = sc.nextInt();
            System.out.println(x-y);
            
        } catch (Exception e) {
            // TODO: handle exception
            System.out.println("不是数字");
        }
    }
}
​

Question

自定义异常类，在进行减法运算时，当第一个数大于第二个数的时候，抛出“被减数不能小于减数”，并编写程序进行测试

Code

import java.util.Scanner;
class myException extends Exception {
    private String myString;
    public myException(String myString) {
        this.myString = myString;
    }
    public String getMyString() {
        return myString;
    }
    @Override
    public String toString() {
        return myString;
    }
}
public class test {
    public static void main(String args[]) {
        double i, j;
        Scanner sc = new Scanner(System.in);
        System.out.println("输入减数");
        i = sc.nextInt();
        System.out.println("输入被减数");
        j = sc.nextInt();
        try {
            if (i >= j) {
                System.out.println(i - j);
            }else {
                throw new myException("被减数不能小于减数");
            }
        }catch (myException e) {
            // TODO: handle exception
            System.out.println(e);
            
        }
    }
}
​

## Writer

通大咸鱼