Undefined Reference

C++
1

Hi guys :wave:t4:

UndefinedRef
UndefinedRef1212×539 84 KB

Can anyone please help me to solve Undefined Reference error?

2

There is no definition for Length::Length(int) in your Length class.

1 Like
3

Thank you POMPOMBALLS for replying. I think we better check our code for clarity

headerfile
headerfile1265×638 58 KB

Implementfile
Implementfile1101×837 72.8 KB

MainFile
MainFile1080×935 77.4 KB

After analysing my code, can you please tell me where I am incurring this error?

4

Use

3 backticks (`) to write your code so that the problem can be reproduced easily.
5

Sure buddy!
Folder name is EqualityOperator

EqualityOp.hpp

#ifndef EQUALITYOPERATOR_EQUALITYOP_H
#define EQUALITYOPERATOR_EQUALITYOP_H

class Length{
    public:
        explicit Length(int value);
        bool operator==(const Length& source)const;
        bool operator!=(const Length& source)const;
        bool operator==(int value)const;
        bool operator!=(int other)const;
    private:
        int value;
};

#endif

EqualityOp.cpp

#include "EqualityOp.hpp"

Length::Length(int value): value{value} {}

bool Length::operator==(const Length& source)const{
    return value == source.value;
}

bool Length::operator!=(const Length& source)const{
    return !(operator==(source));
}

bool Length::operator==(int value)const{
    return this->value == value;
}

bool Length::operator!=(int other)const{
      return !(value == other);
}

MainEqual.cpp

#include "EqualityOp.hpp"
#include <iostream>

using namespace std;

int main(){
    Length first{10};
    Length second{10};

    cout<<((first == second)? "true":"false")<<endl;

    cout<<boolalpha<<first.operator==(second)<<endl;
    if(first != second)
        cout<<"true"<<endl;
    else {cout<<"false"<<endl;}

    cout<<((first == 10)? "true":"false")<<endl;
    cout<<((first != 20)?"yes":"no")<<endl;

    return 0;
}
6

Your files must be known to the linker. LNK2019 (in Visual Studio) is a linking error for unresolved external symbol(s). Make sure your file is included in the project as shown (again, Visual Studio). The code works as it should.

image
image263×911 18.8 KB

For more information, look here (discussion).

1 Like
7

I’ll check it and will get back to you buddy. I appreciate your effort!
:smiley:

8

I am using Visual Studio Code rather than Visual Studio. Can this problem be solved in VS Code or should I start to use Visual Studio for further practice?

9

It should be available in Workspace settings. If not, then there should be a setting for syncing project files.

1 Like