【java】笔记10：类与对象——本章练习

题目1：

代码如下：

import java.util.Scanner;
public class Input{
	public static void main(String[]args){
	    Circle c=new Circle();
		PassObject yuan=new PassObject();
		System.out.println("r"+"\t"+"times");
		yuan.printAreas(c,5);
}
}

class Circle{
double pi=Math.PI;
double r;
public double suu(double r){
double s=pi*r*r;
return s;
}
}

class PassObject{

	public void printAreas(Circle c,int times)
	{
for(int i=1;i<6;i++)
{
System.out.println((double)i+"\t"+new Circle().suu(i));
}
	}
}

题目2：

代码如下：

import java.util.Scanner;
import java.util.Random;
public class Input{
	public static void main(String[]args){
		Scanner myScanner = new Scanner(System.in);
   int[][]a=new int[3][3];
   String[]b=new String[3];
  
   for(int i=0;i<3;i++)
   {
   	System.out.println("请输入你要出的拳（0-拳头，1-剪刀，2-布）：");
   	int your=myScanner.nextInt();
   int n  =	new Tom().panduan(your);
   if(n==0)  your=myScanner.nextInt();
    Random random=new Random();
  int comp=random.nextInt(3);
   b[i]=new Tom().sit(your,comp);
  System.out.println("===========================");
  System.out.println("局数"+"\t玩家的出拳"+"\t电脑的出拳"+"\t输赢情况");
 System.out.println(i+1+"\t"+your+"\t\t"+comp+"\t\t"+b[i]);
  System.out.println("===========================");
 a[i][0]=i+1;
 a[i][1]=your;
 a[i][2]=comp;
   }
 System.out.println("局数"+"\t\t玩家的出拳"+"\t电脑的出拳"+"\t输赢情况");
  for(int i=0;i<3;i++)
  	{for(int j=0;j<3;j++)
  		{System.out.print(a[i][j]+"\t\t");}
  		System.out.print(b[i]);
  		System.out.println();
     }

}
}
class Tom{

     public String sit(int your,int comp){
     	if(your==0&&comp==2) return "你赢了";
     	else if(your==1&&comp==0) return "你赢了";
     	else if(your==2&&comp==1) return "你赢了";
     	else if(your==comp) return "平局";
     	else return "你输了";
     }

     public int panduan(int num){
       if(num>2||num<0)
       	{
       		System.out.println("你的输入有误，请输入0-2之间的数");
       		return 0;

        }
        else return 1;
     }
    
}

结果如下：