Question

我遇到的问题是当我尝试在3个类对象的数组中设置一些类变量时，我得到一个错误，指出函数所需的变量未在main函数的范围内声明

我仍然是新手，并将我的界面与我的实现分开，我觉得它有时会让人感到困惑。

我一直在查看本网站和其他网站上的其他一些示例，我无法确切地知道我的问题是什么以及如何解决它。

interface.h文件：

    #ifndef INTERFACE_H
    #define INTERFACE_H

    #include <iostream>
    #include <string>
    #include <fstream>

    using namespace std; // I know this is a programming sin to include inside a header file but my textbook wants me to do it this way

    class student
    {
    public:
        student(); // class constructor
        void setstudent(string studentName, string ID, string studentNumber, string diploma); // Function im using to set objects in array object

    private:
        string studentName;
        string ID;
        string studentNumber; // class variables
        string diploma;
        int averageMark;
        string codes [5];
        int marks [5];
    };


    #endif // INTERFACE_H

implementation.cpp文件：

#include <iostream>
#include "interface.h"

using namespace std;

student::student()
{
    studentName = "";
    ID = "";
    studentNumber = ""; // constructor to initialise all class variables
    diploma = "";
    averageMark = 0;
    codes [5] = {"", "", "", "", ""};
    marks [5] = {0, 0, 0, 0, 0};
}

void student::setstudent(string studentName, string ID, string studentNumber, string diploma) // function to set class variables
{
    cout << "Please enter a student name" << endl;
    cin.getline(studentName);

    cout << "Please enter a unique student ID" << endl;
    cin.getline(ID);

    cout << "Please enter a unique student number" << endl;
    cin.getline(studentNumber);

    cout << "Please enter diploma name" << endl;
    cin.getline(diploma)
    if (diploma == "Garden Design")
    {
        codes[5] = {"G1","G2","G3","G4","G5"};
    }
    else if (diploma == "Gourmet Cooking")
    {
        codes[5] = {"C1","C2","C3","C4","C5"};
    }
}

main.cpp文件：

#include <iostream>
#include "interface.h"

using namespace std;

int main()
{
    student studentDetails[3]; // Creation of class array object to store 3 objects / Maybe ive declared my array to hold 3 class objects incorrectly?
    for (int i = 0; i < 3; i++)
    {
        studentDetails[i].setstudent(studentName, ID, studentNumber, diploma); // function call to set class variables for the objects

    }

    return 0;
}

如果有人能指出我做错了什么并指出我正确的方向将非常感激。

CodeBlocks错误：

||=== Build: Debug in student (compiler: GNU GCC Compiler) ===|
C:\Users\nicbe\Desktop\Student\student\main.cpp||In function 'int main()':|
C:\Users\nicbe\Desktop\Student\student\main.cpp|12|error: 'studentName' was not declared in this scope|
C:\Users\nicbe\Desktop\Student\student\main.cpp|12|error: 'ID' was not declared in this scope|
C:\Users\nicbe\Desktop\Student\student\main.cpp|12|error: 'studentNumber' was not declared in this scope|
C:\Users\nicbe\Desktop\Student\student\main.cpp|12|error: 'diploma' was not declared in this scope|
||=== Build failed: 4 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|

Answer 1

错误正是它所说的：未被声明。

在您的主要功能中：

studentDetails[i].setstudent(studentName, ID, studentNumber, diploma);

突然，这四个论点凭空出现（？）。不确定您是否刚刚排除了该部分或什么。

未在main函数c ++中声明的类变量

1 个答案: