随机输入数四则运算

package 运算;
import java.text.DecimalFormat;
import java.util.Scanner;
public class Ys {

public static void main(String[] args) {
String condition = "";
Ys ys = new ys();
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);ys.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("无法识别改运算符");
}
}
}