写一个计算器，要求实现加减乘除功能，并且能够循环接收新的数据，通过用户交互实现。
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String input = "yes";//控制循环执行
while(input.equals("yes")){
System.out.println("请输入您要做的运算符号：");
String sign = scanner.next();
if(sign.equals("+")){
System.out.println("请输入两个数");
double num1 = scanner.nextDouble();
double num2 = scanner.nextDouble();
add(num1,num2);
}else if(sign.equals("-")){
System.out.println("请输入两个数");
double num1 = scanner.nextDouble();
double num2 = scanner.nextDouble();
sub(num1,num2);
}else if(sign.equals("*")){
System.out.println("请输入两个数");
double num1 = scanner.nextDouble();
double num2 = scanner.nextDouble();
mul(num1,num2);
}else if(sign.equals("/")){
System.out.println("请输入两个数");
double num1 = scanner.nextDouble();
double num2 = scanner.nextDouble();
div(num1,num2);
}else{
System.out.println("您的输入有误！");
}
System.out.println("是否继续操作，按“yes”继续，" +
"其他任意键结束");
input = scanner.next();
}
System.out.println("感谢使用!");
scanner.close();
}
//加
public static void add(double a,double b){
double result = a + b;
System.out.println("计算结果为："+result);
}
//减
public static void sub(double a,double b){
double result = a - b;
System.out.println("计算结果为："+result);
}
//乘
public static void mul(double a,double b){
double result = a * b;
System.out.println("计算结果为："+result);
}
//除
public static void div(double a,double b){
if(b == 0){
System.out.println("除数不能为0！");
return;
}
double result = a / b;
System.out.println("计算结果为："+result);
}
输出示例：
