Lab 4: 簡易科學計算機

Lab 4-1: 計算機功能選擇 (40%)

• 輸入：要執行的計算功能，分別如下：
  1. 加 (+)
  2. 減 (-)
  3. 乘 (*)
  4. 除 (/)
• 輸出：所選擇的運算子字元 (i.e. +, -, *, /)
• 檔名：lab4_1_<學號>.cpp (e.g. lab4_1_106062802.cpp)

程式需提示使用者輸入需要的運算功能，輸出該運算功能的運算子字元。

Simple scientific calculator
1) plus (+)
2) minus (-)
3) multiplication (*)
4) division (/)
Please select the operator: <1-4>
You selected: <+, -, *, />

Example:

$ ./a.out
Simple scientific calculator
1) plus (+)
2) minus (-)
3) multiplication (*)
4) division (/)
Please select the operator: 3
You selected: *

Reference Code:

if ... else ...: Credit: 許景煬 (107071017)

#include <iostream>
#include <iomanip>

int main(void)
{
    int a = 0;
    std::cout << "Simple scientific calculator\n"
              << "1) plus (+)\n"
              << "2) minus (-)\n"
              << "3) multiplication (*)\n"
              << "4) division (/)\n"
              << "Please select the operator: "
              << std::endl;
    std::cin >> a;
    if (a == 1)
    {
        std::cout << "You selected: "
                  << "+"
                  << std::endl;
    }
    else if (a == 2)
    {
        std::cout << "You selected: "
                  << "-"
                  << std::endl;
    }
    else if (a == 3)
    {
        std::cout << "You selected: "
                  << "*"
                  << std::endl;
    }
    else if (a == 4)
    {
        std::cout << "You selected: "
                  << "/"
                  << std::endl;
    }
    else
    {
        std::cout << "Your operator is not in here!!!!!!!"
                  << std::endl;
    }
}

switch ... case ...: Credit: 陳欣妤 (110021108)

#include <iostream>
using namespace std;

int main()
{
    int a;
    cout << "Simple scientific calculator" << '\n'
         << "1) plus (+)" << '\n'
         << "2) minus (-)" << '\n'
         << "3) multiplication (*)" << '\n'
         << "4) division (/)" << '\n'
         << "Please select the operator: ";
    cin >> a;
    switch (a)
    {
    case 1:
        cout << "You selected: +" << endl;
        break;
    case 2:
        cout << "You selected: -" << endl;
        break;
    case 3:
        cout << "You selected: *" << endl;
        break;
    case 4:
        cout << "You selected: /" << endl;
        break;
    default:
        cout << "You selected: ?" << endl;
    }
    return 0;
}