我需要帮助弄清楚如何将getline纳入PresentStringPrompt，以摆脱重复的代码

Question

这个程序要求您输入三个朋友和他们的披萨切片的直径。
然后，它计算披萨的面积，并看到谁的切片最大。

我需要一些帮助，尝试将getline放入我的字符串函数中，以摆脱代码中的重复。

#include <iostream>
#include <cmath>
#include <iomanip>
#include <string>
using namespace std;
string presentStringPrompt(string);
double presentDoublePrompt(string);
double computeAreaOfCircle(double);

const double pi = 3.14159;

int main() {

    string first;
    string second;
    string third;
    double diameter;
    double radius;
    double area1;
    double area2;
    double area3;
    cout << "Enter the name of the first friend: ";
    getline(cin, first);
    cout << "Enter " << first << " pizza diameter : ";
    cin >> diameter;
    cin.ignore();
    radius = diameter / 2;
    area1 = pi * radius * radius;
    cout << "Enter the name of the second friend: ";
    getline(cin, second);
    cout << "Enter " << second << " pizza diameter : ";
    cin >> diameter;
    cin.ignore();
    radius = diameter / 2;
    area2 = pi * radius * radius;
    cout << "Enter the name of the third friend: ";
    getline(cin, third);
    cout << "Enter " << third << " pizza diameter : ";
    cin >> diameter;
    radius = diameter / 2;
    area3 = pi * radius * radius;
    cout << showpoint << fixed << setprecision(1);
    cout << " The area of " << first << "'s pizza is " << area1 << " inches squared" << endl;
    cout << " The area of " << second << "'s pizza is " << area2 << " inches squared" << endl;
    cout << " The area of " << third << "'s pizza is " << area3 << " inches squared" << endl;
    if (area1 >= area2 && area1 >= area3) {
        cout << first << " has the largest slice of pizza." << endl;
    }
    else if (area2 >= area1 && area2 >= area3) {
        cout << second << " has the largest slice of pizza." << endl;
    }
    else {
        cout << third << " has the largest slice of pizza" << endl;
    }
    cin.ignore();
    cin.get();
    return 0;
}
string presentStringPrompt(string) {
    string value;
    getline(cin,value);
    return value;
    cin.ignore();
}
double presentDoublePrompt(string) {
}
double computeAreaOfCircle(double) {
}

Answer 1

在您以前的格式文本提取中的输入流中留下了一个'n'字符。

这就是为什么第一个后续getline()语句之后失败的原因。

您可以在此处获取有关如何解决该问题的更多信息：

为什么std :: getline((在格式提取后跳过输入？

Answer 2

内部内部您必须调用此功能

int main()
{
     cout << "Enter the name of the first friend: ";
     first = presentStringPrompt(first);//or you can use pass by reference that way you don't have to do first = 
     cout << "Enter " << first << " pizza diameter : ";
     cin >> diameter;
     cin.ignore();
}

---

string presentStringPrompt(string value) 
{
   getline(cin,value);
   return value;
}

Answer 3

模板怎么样？

template <typename T> question(char * question)
{
    T reply;
    cout << question;
    cin >> reply;
    cin.ignore();
    return reply;
}

用作

double diameter = question("Enter " + first + " pizza diameter :");

---

几个注：

• 如果您将"用于字符串，则不需要终止char，它是由编译器添加的。

• 返回后不要添加行，不会执行它。