Question

我是一个新的相对较新的程序员，我决定用C ++编写代码。目前，我正在开发转换器应用程序项目。我希望从金钱转换到重量到温度，如果可能的话，甚至更多的东西。我写了一段很好的代码，我想检查它是否有效。由于某种原因，代码确实编译但是所有的应用程序确实给了我一个空白的屏幕，没有区域输入值或任何东西。它没有显示我写的指令或其他任何内容。

以下是代码：

#include "std_lib_facilities.h"

int a = 0;
int b = 0;
int c = 0;

int money()
{
    cout << "This will convert CAD to either USD or EUR\n";
    cout << "Please input USD or EUR followed by an enter keystroke for conversion\n";
    string a;
    while(cin >> a){
        if( a == "USD"){
            cout << "If you would like to convert USD into CAD, enter 1.\n";
            cout << "If you would like to convert CAD into USD, enter 2.\n";
            int x;
            cin >> x;
            if( x == 1){
                cout << "Please enter the amount you wish to convert.\n";
                double j;
                cin >> j;
                double k = j*1.29;
                cout << j << "USD is " << k << "CAD.\n";

            }
            if ( x == 2){
                cout << "Please enter the amount you wish to convert.\n";
                double o;
                cin >> o;
                double p = o*0.77;
                cout << o << "CAD is " << p << "USD.\n";
            }
        }
        if( a == "EUR"){
            cout << "If you would like to convert EUR into CAD, enter 1.\n";
            cout << "If you would like to convert CAD into EUR, enter 2.\n";
            int y;
            cin >> y;
            if(y == 1){
                cout << "Please enter the amount you wish to convert.\n";
                double g;
                cin >> g;
                double h = g*1.46;
                cout << g << "EUR is " << h << "CAD.\n";

            }
            if(y == 2){
                cout << "Please enter the amount you wish to convert.\n";
                double z;
                cin >> z;
                double x = z*0.69;
                cout << z << "CAD is " << x << "EUR.\n";
            }

        }
    }

}

int weight()
{
    cout << "This will convert pounds to kilograms.\n";
    cout << "Please input the amount you wish to convert.\n";
}

int temperature()
{

}

int setup()
{
    cout << "Please enter either a,b or c for the corresponding conversions.\n";
    cout << "(Where a is for currency, b is for weight, and c is for temperature.\n";
    string a;
    while ( cin >> a){
        if( a == "a"){
            int money();
            }
        if( a == "b"){
            int weight();
        }
        if( a == "c"){
            int temperature();
        }
    }
}

int main()
{
    cout << "Welcome to the ultimate converter app.\n";
    int setup();
    return 0;
}

任何帮助都将不胜感激。

编辑：对每个人来说都很麻烦。感谢所有人，我已经意识到我已经实现了我已经宣布了一项功能，而不是打电话给我。

Answer 1

将class Program < ApplicationRecord has_many :courses, dependent: :nullify end class Course < ApplicationRecord has_many :sessions, class_name: "CourseSession", inverse_of: :course, dependent: :destroy belongs_to :program end class CourseSession < ApplicationRecord belongs_to :course end替换为int setup();中的setup();。

main()只是声明函数，但不要调用它。

您还必须更正int setup();：

setup()

void setup() { cout << "Please enter either a, b or c for the corresponding conversions." << endl; cout << "Where a is for currency, b is for weight, and c is for temperature." << endl; string str; while (cin >> str) { if (str == "a") { money(); } else if (str == "b") { weight(); } else if (str == "c") { temperature(); } else { cout << "Invalid input." << endl; } } }，money()和weight()也必须返回temperature()类型。

Answer 2

我认为当你在C ++中调用一个函数时，你只需输入名称（假定它被定义），你不要在函数名之前写一个类型，试试这个...

    #include <iostream>
using namespace std;

int a = 0;
int b = 0;
int c = 0;

int money()
{
    cout << "This will convert CAD to either USD or EUR\n";
    cout << "Please input USD or EUR followed by an enter keystroke for conversion\n";
    string a;
    while(cin >> a){
        if( a == "USD"){
            cout << "If you would like to convert USD into CAD, enter 1.\n";
            cout << "If you would like to convert CAD into USD, enter 2.\n";
            int x;
            cin >> x;
            if( x == 1){
                cout << "Please enter the amount you wish to convert.\n";
                double j;
                cin >> j;
                double k = j*1.29;
                cout << j << "USD is " << k << "CAD.\n";

            }
            if ( x == 2){
                cout << "Please enter the amount you wish to convert.\n";
                double o;
                cin >> o;
                double p = o*0.77;
                cout << o << "CAD is " << p << "USD.\n";
            }
        }
        if( a == "EUR"){
            cout << "If you would like to convert EUR into CAD, enter 1.\n";
            cout << "If you would like to convert CAD into EUR, enter 2.\n";
            int y;
            cin >> y;
            if(y == 1){
                cout << "Please enter the amount you wish to convert.\n";
                double g;
                cin >> g;
                double h = g*1.46;
                cout << g << "EUR is " << h << "CAD.\n";

            }
            if(y == 2){
                cout << "Please enter the amount you wish to convert.\n";
                double z;
                cin >> z;
                double x = z*0.69;
                cout << z << "CAD is " << x << "EUR.\n";
            }

        }
    }

}

int weight()
{
    cout << "This will convert pounds to kilograms.\n";
    cout << "Please input the amount you wish to convert.\n";
}

int temperature()
{

}

int setup()
{
    cout << "Please enter either a,b or c for the corresponding conversions.\n";
    cout << "(Where a is for currency, b is for weight, and c is for temperature.\n";
    string a;
    while ( cin >> a){
        if( a == "a"){
             money();
            }
        if( a == "b"){
             weight();
        }
        if( a == "c"){
             temperature();
        }
    }
}

int main()
{
    cout << "Welcome to the ultimate converter app.\n";
    setup();
    return 0;
}

未调用C ++函数

2 个答案: