第一章 做业一

import java.text.DecimalFormat;import java.util.Scanner;public class Zhidao {		public static void main(String[] args) {		String condition = "";		Zhidao zhidao = new Zhidao();		do{		Scanner scanner = new Scanner(System.in);		try{		System.out.print("请输入第一个数：");		double x = scanner.nextDouble();		System.out.print("请输入第二个数：");		double y = scanner.nextDouble();		System.out.print("请输入运算符：");		String s = scanner.next();		char z = s.charAt(0);		zhidao.yunsuan(x, y, z);		}catch(Exception e){			System.out.println("请输入正确的数据！");		}		System.out.print("是否继续？continue：继续，任意字符：结束");		condition = scanner.next();			}while("continue".equals(condition));	}		public static void yunsuan(double x,double y,Character z){		DecimalFormat r=new DecimalFormat(); 		r.applyPattern("#0.00");		if(z.equals('+')){			System.out.println(x+"+"+y+"=" + r.format((x+y)));		} else if(z.equals('-')){			System.out.println(x+"-"+y+"=" + r.format((x-y)));		} else if(z.equals('*')){			System.out.println(x+"*"+y+"=" + r.format((x*y)));		} else if(z.equals('/')){			if(y==0){				System.out.println("被除数不能为0");			} else{				System.out.println(x+"/"+y+"=" + r.format((x/y)));			}			}else{			System.out.println("没法识别改运算符");		}	}}