Question

首先，我刚刚开始学习C ++，所以如果我给这个标题命名不正确，或者我不知道这意味着什么，请原谅我。如果您确实回答了这个问题，请不要使用我不知道的所有疯狂词汇。谢谢：）。

我目前（正在尝试）制作一个计算器，可以让您选择加减，乘或除。我知道这似乎不太有用，但是在我所做的事情中，我学到了很多东西。

这是我现在拥有的代码：

#include <iostream>
#include <string>
using namespace std;

int add() 
{
    int x;
    int y;
    int sum;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    sum = x + y;

    cout << x << " + " << y << " = " << sum << endl;
}

int subtract() 
{
    int x;
    int y;
    int difference;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    difference = x - y;

    cout << x << " - " << y << " = " << difference << endl;
}

int multiply() 
{
    int x;
    int y;
    int product;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    product = x * y;

    cout << x << " * " << y << " = " << product << endl;
}

int divide() 
{
    int x;
    int y;
    int quotient;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    quotient = x / y;

    cout << x << " / " << y << " = " << quotient << endl;
}


int main()
{
    int Add, Subtract, Multiply, Divide;
    string str;

    cout << "Add, Subtract, Multiply, Divide?: ";

    getline(cin, str);
    if (str == (cin, add));
    cout << "Starting process " << str << "..." << endl;
        add();


    getline(cin, str);
    if (str == (cin, "subtract"));
    cout << "Starting process " << str << "..." << endl;
        subtract();    

}

我遇到的问题在main()部分中。我希望程序通过getline读取用户输入，然后将其与预定变量进行比较。然后，我尝试创建一个if语句，如果用户输入例如是“ add”，则if语句将读取该内容，然后运行我的add函数。

我已经深入到getline部分，但是如您所见，if语句什么也不做。我以为可能是这样的：

if (str == "add")
cout << "Starting Process" << str << "..." << endl;
    add();

让我失望的是一些错误。我不确定如何构造if语句，我们将不胜感激。

谢谢，尼克

Answer 1

因此，我进行了一些研究，最终使它起作用。造成您的不便，敬请见谅。不过，我可以看到，这是一个非常活跃和友善的社区。我将确保将其作为“第一道防线”再次提及。这是我的最终代码：

#include <iostream>
using namespace std;

void add() 
{
    int x;
    int y;
    int sum;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    sum = x + y;

    cout << x << " + " << y << " = " << sum << endl;
}

void subtract() 
{
    int x;
    int y;
    int difference;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    difference = x - y;

    cout << x << " - " << y << " = " << difference << endl;
}

void multiply() 
{
    int x;
    int y;
    int product;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    product = x * y;

    cout << x << " * " << y << " = " << product << endl;
} 

void divide() 
{
    int x;
    int y;
    int quotient;

    cout << "Enter the value for x: ";
    cin >> x;
    cout << "Enter the value for y: ";
    cin >> y;

    quotient = x / y;

    cout << x << " / " << y << " = " << quotient << endl;
}

int main()
{
    int Add, Subtract, Multiply, Divide;
    string str;

    cout << "Add, Subtract, Multiply, Divide? (Letters are case sensitive): ";
    getline(cin, str);

    if (str == "Add")
    {
        cout << "Starting Process " << str << "..." << endl;
            add();
    }

    //getline(cin, str);
    if (str == "Subtract")
    {
        cout << "Starting process " << str << "..." << endl;
            subtract();
    }   

    //getline(cin, str);
    if (str == "Multiply")
    {
        cout << "Starting process " << str << "..." << endl;
            multiply();
    }

    //getline(cin, str);
    if (str == "Divide")
    {
        cout << "Starting process " << str << "..." << endl;
            divide();
    }

}

将getline（）与'If'语句中的预定变量进行比较

1 个答案: