我需要帮助弄清楚如何将 getline 放入 presentStringPrompt 以摆脱重复代码

Posted 2023-02-22

【中文标题】我需要帮助弄清楚如何将 getline 放入 presentStringPrompt 以摆脱重复代码

【英文标题】：I need help figuring out how to put getline into presentStringPrompt to get rid of repetitious code

【发布时间】：2017-06-30 03:01:00

【问题描述】：

这个程序要求你输入三个朋友和他们的披萨片的直径。 然后它计算比萨饼的面积并查看谁拥有最大的切片。

我需要一些帮助来尝试将 getline 放入我的字符串函数中以消除代码中的重复。

#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: \0";
    getline(cin, first);
    cout << "Enter " << first << " pizza diameter : \0";
    cin >> diameter;
    cin.ignore();

    radius = diameter / 2;
    area1 = pi * radius * radius;

    cout << "Enter the name of the second friend: \0";
    getline(cin, second);
    cout << "Enter " << second << " pizza diameter : \0";
    cin >> diameter;
    cin.ignore();

    radius = diameter / 2;
    area2 = pi * radius * radius;

    cout << "Enter the name of the third friend: \0";
    getline(cin, third);
    cout << "Enter " << third << " pizza diameter : \0";
    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\0" << endl;
    cout << " The area of " << second << "'s pizza is " << area2 << " inches squared\0" << endl;
    cout << " The area of " << third << "'s pizza is " << area3 << " inches squared\0" << 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) 

【问题讨论】：

使用 std:array 或 std::vector 存储名称，并相应地将输入包装到 for() 循环中

【参考方案1】：

在您之前提取的格式化文本的输入流中留下了一个 '\n' 字符。

这就是为什么随后的第一个 getline() 语句随后失败的原因。

您可以在此处获取有关如何解决此问题的更多信息：

Why does std::getline() skip input after a formatted extraction?

【参考方案2】：

在 main 你必须调用这个函数

int main()

     cout << "Enter the name of the first friend: \0";
     first = presentStringPrompt(first);//or you can use pass by reference that way you don't have to do first = 
     cout << "Enter " << first << " pizza diameter : \0";
     cin >> diameter;
     cin.ignore();

---

string presentStringPrompt(string value) 

   getline(cin,value);
   return value;

【参考方案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 :");

---

几点说明：

如果使用""作为字符串，则不需要终止字符，由编译器添加。

return 后不要添加行，它不会被执行。