写一个java的计算器

以下是一个简单的Java计算器的代码示例：

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("Enter first number: ");
        double num1 = scanner.nextDouble();

        System.out.print("Enter second number: ");
        double num2 = scanner.nextDouble();

        System.out.print("Enter operator (+, -, *, /): ");
        char operator = scanner.next().charAt(0);

        double result;

        switch (operator) {
            case '+':
                result = num1 + num2;
                break;
            case '-':
                result = num1 - num2;
                break;
            case '*':
                result = num1 * num2;
                break;
            case '/':
                result = num1 / num2;
                break;
            default:
                System.out.println("Invalid operator");
                return;
        }

        System.out.println(num1 + " " + operator + " " + num2 + " = " + result);
    }
}

该计算器可以接收两个数字和运算符（加号、减号、乘号、除号）作为输入，并输出计算结果。在该示例中，使用了Scanner类来从命令行读取输入。计算逻辑使用了switch语句实现