函数调用_猜数字和简易计算器

Posted 2020-09-02

package app1;
import java.util.*;
public class TestFunction{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        System.out.print("请选择一项应用:\n1.猜数字\n2.简易计算器");
        int n=sc.nextInt();
        switch(n){
            case 1:
               guessNum();
            break;
            
            case 2:
                System.out.print("***请操作计算器***\n请输入一个数:");
                int num_1=sc.nextInt();
                System.out.print("请输入一个运算符:");
                char ch=sc.next().charAt(0);    //输入一个字符
                System.out.print("请再输入一个数:");
                int num_2=sc.nextInt();
                jiSuanQi(num_1,ch,num_2);
            break;
            
            case 3:
            break;
            
            default:
            break;
            
        }
    }
    
    //写一个猜数字函数,让系统随机产生一个数字,用户从键盘上输入一个数
    public static void guessNum(){
        int ran=(int)(Math.random()*10);
        System.out.print("猜数字游戏,请输入一个数(0~9):");
        
        do{
            int n=sc.nextInt();
            if(ran==n){
                System.out.print("我去,竟然被你蒙对了(。＿。)");
                flat=false;
            }else if(ran>n){
                System.out.print("猜小了,请重猜:");
                flat=true;
            }else if(ran<n){
                System.out.print("猜大了,请重猜:");
                flat=true;
            }
        }while(flat);//如果条件换成n!=ran,是不行的 因为n这个局部变量的作用域不在{}外
        
        
    }
    
    //写一个简易计算器的函数
    public static void jiSuanQi(int num_1,char ch,int num_2){
        switch(ch){
            case ‘+‘:
            int sum=num_1+num_2;
            System.out.println("等于"+sum);
            break;
            
            case ‘-‘:
            int reduce=num_1-num_2;
            System.out.println("等于"+reduce);
            break;
            
            case ‘*‘:
            int mul=num_1*num_2;
            System.out.println("等于"+mul);
            break;
            
            case ‘/‘:
            double div=num_1/num_2;
            System.out.println("等于"+div);
            break;
            
            default:
            System.out.println("输入有误!");
            break;
        }
    }
}

本文出自 “ChristianWyld's Blog” 博客，请务必保留此出处http://wyld123.blog.51cto.com/12619448/1903245