技術標籤：javajava

寫一個計算器，實現加減乘除功能，並且能夠迴圈接收新資料，通過使用者互動實現

public class HomeWork01 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("請輸入要操作的數字，結束時輸入quit回車");
        System.out.println("輸入計算型別（+，-，*，/）");
        System.
 
out.println("每輸完數字或者符號都要按回車鍵");
        String str = "";
        Double a = 0.0;
        Double b = 0.0;
        Double result = 0.0;
        while (scanner.hasNextDouble()){
            a = scanner.nextDouble();
            break;

        }
        while (scanner.hasNextLine()){
            str =
 
 scanner.next();
            switch (str){
                case "+":
                    b = scanner.nextDouble();
                    result = add(a,b);
                    a = result;
                    System.out.println(result);
                    break;
                case "-"
 
:
                    b = scanner.nextDouble();
                    result = reduce(a,b);
                    a = result;
                    System.out.println(result);
                    break;
                case "*":
                    b = scanner.nextDouble();
                    result = ride(a,b);
                    a = result;
                    System.out.println(result);
                    break;
                case "/":
                    b = scanner.nextDouble();
                    result = except(a,b);
                    a = result;
                    System.out.println(result);
                    break;
            }
            if (str.equals("quit")){
                System.out.println("退出計算機");
                break;
            }
        }
        scanner.close();
    }

    //加法
    public static Double add(Double d1,Double d2){
        return d1 + d2;
    }
    //減法
    public static Double reduce(Double d1,Double d2){
        return d1 - d2;
    }
    //乘法
    public static Double ride(Double d1,Double d2){
        return d1 * d2;
    }
    //除法
    public static Double except(Double d1,Double d2){
        return d1 / d2;
    }
}

效果如下：

請輸入要操作的數字，結束時輸入quit回車
輸入計算型別（+，-，*，/）
每輸完數字或者符號都要按回車鍵
56.26
+
89.26
145.52
-
45.52
100.0
*
10
1000.0
/
25
40.0
quit
退出計算機

Process finished with exit code 0

有更加簡潔的方法，歡迎評論交流