java实现计算器计算代码

以下是一个简单的 Java 计算器示例程序：

import java.util.Scanner;

public class Calculator {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double num1, num2, result;
        char operator;

        System.out.print("请输入第一个数字: ");
        num1 = scanner.nextDouble();

        System.out.print("请输入运算符 (+, -, *, /): ");
        operator = scanner.next().charAt(0);

        System.out.print("请输入第二个数字: ");
        num2 = scanner.nextDouble();

        switch (operator) {
            case '+':
                result = num1 + num2;
                System.out.println(num1 + " + " + num2 + " = " + result);
                break;
            case '-':
                result = num1 - num2;
                System.out.println(num1 + " - " + num2 + " = " + result);
                break;
            case '*':
                result = num1 * num2;
                System.out.println(num1 + " * " + num2 + " = " + result);
                break;
            case '/':
                result = num1 / num2;
                System.out.println(num1 + " / " + num2 + " = " + result);
                break;
            default:
                System.out.println("无效的运算符!");
                break;
        }
    }
}

该程序会提示用户输入两个数字和一个运算符，然后计算并输出结果。注意，此程序没有处理除数为零的情况。