// 利用Scanner 和 switch 写一个简易的 加减乘除 计算器；
public class Computer {
    public static void main(String[] args) {
        // 创建Scanner 扫描器接收用户的输入
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入第一数字：");
        double a = scanner.nextDouble();
        System.out.println("请输入运算符：");
        String b = scanner.next();
        System.out.println("请输入第二个数字：");
        double c = scanner.nextDouble();
        switch (b){
            case "+":
                double add = a+c;
                System.out.println(a+"+"+c+"的结果为："+add);
                break;
            case "-":
                double sub = a-c;
                System.out.println(a+"-"+c+"的结果为："+sub);
                break;
            case "*":
                double mul = a*c;
                System.out.println(a+"*"+c+"的结果为："+mul);
                break;

            case "/":
                double dev = a/c;
                System.out.println(a+"/"+c+"的结果为："+dev);
                break;

            default:
                System.out.println("请按要求输入运算符：+ - * /");
                break;
        }
        scanner.close(); //关闭扫描器
    }
}