CODEWITHSUNDEEP
c++
Phroton
Phroton

Reputation: 1

Error: "x" was not declared on this scope when using class files

I'm having a problem when using the class files and the compiler error says "error: 'x' was not declared on this code" while it points out the cout, string, and endl. I have already wrote "#include " and "#include " in both header, class, and main file.

(Sorry for my English) I'm just a beginner and I wanted to know the basics

Added #include and #include in both files

//Main File (main.cpp)
#include <iostream>
#include "test.h"
#include <string>
using namespace std;

int main()
{
    test *person = new person("Phroton",14)
    person.Display();
    return 0;
}


//test.h
#ifndef TEST_H
#define TEST_H
#include <iostream>
#include <string>
class test
{
    private:
        string name;
        int age;
    public:
        void Display(){
            cout << "I'm " << name << " and I'm " << age << "years old" << endl;
        }
};

#endif // TEST_H

//test.cpp (There is no problem with this file at all)
#include "test.h"
#include <iostream>
#include <string>
test::test(string iname, int iage)
{
    name = new string;
    age = new int;
    *name = iname;
    *age = iage;
}

test::~test()
{
    delete name;
    delete age;
    cout << "Info Deleted" << endl;
}

Upvotes: 0

Views: 1375

Answers (1)

P.W
P.W

Reputation: 26800

Answering the specific problem you have asked:

This is because you have not specified the namespace cout and endl belong to in the file test.h.

The statement in Display should be:

std::cout << "I'm " << name << " and I'm " << age << "years old" << std::endl;

The alternative to this is the using namespace std declaration but this is considered a bad practice (especially in a header file).

Note:

  • You do not need using namespace std in main.cpp as you are not using any functions from the std namespace there. Even if you do, use the std::name instead of the using declaration.

  • Member function definitions are usually present in .cpp files. So you can define the function Display to test.cpp.

  • Also consider moving away from raw pointers to smart pointers.

Upvotes: 0

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