Member Avatar for charles.dupree.37

Hi, I was wondering if someone could look at this person class I am working on. The first part is the class header with the constructors for the class. In the second part I am trying to write the code but when I declare the get_age and get_name objects I get an error that states --- declaration is incompatible with "std::string person::get_name() const" I get the same error for the get_age. Can someone help to explain to me what I am doing wrong? Thank YOU, C.D.

#ifndef Lab10

#define Lab10

#include <string>

using namespace std ;

class person

{

public:

    person()    ;

    person( string pname, int page ) ;

    string get_name() const ;

    int get_age() const ;

private:

    string name ;

    int age ;

} ;

#endif






#include "Lab10.h"

#include <iostream>

#include <string>

person :: person()

{ 

    int page = 0 ;

}

 void person :: get_name() // This is where the error is !!!!!!!!!!!!!!

{

    cout << "Please enter the name of the person ";

    getline(cin,name) ;

}

int person :: get_age()  // This is where the error is !!!!!!!!!!!!!!!

{

    cout << "Please enter the age of the person " ;

    cin >> age ;

    return age ;

}
  • 3 Contributors
  • 4 Replies
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  • Latest Post Latest Post by charles.dupree.37

Dani AI

Generated

You are hitting a classic signature mismatch: a member function’s declaration and its out-of-class definition must match exactly, including return type and qualifiers such as const. If the declaration is ... get_name() const, then the definition must also end with const. Also, getters should not perform I/O or modify the object; keep them read-only and move prompting/setting into separate functions. See cv-qualified member functions on cppreference for details: cv-qualified member functions.

Another issue in your default constructor: int page = 0; declares a local variable and leaves the member age uninitialized. Initialize data members with a member-initializer list instead. A clean design is to separate the data model (the person class) from I/O, e.g., provide setters or a read_from(std::istream&) helper.

Example sketch:

#ifndef PERSON_H
#define PERSON_H

#include <string>
#include <iosfwd>

class person {
public:
    person() : name(), age(0) {}
    person(std::string pname, int page) : name(std::move(pname)), age(page) {}

    const std::string& get_name() const { return name; }
    int get_age() const { return age; }

    void set_name(const std::string& pname) { name = pname; }
    void set_age(int page) { age = page; }

    void read_from(std::istream& in); // define in .cpp
private:
    std::string name;
    int age;
};
#endif

Finally, avoid using namespace std; in headers to prevent namespace pollution (Core Guidelines: SF.7). Constructors and initialization are covered here: Constructors and member initializers.

Recommended Answers

All 4 Replies

Member Avatar for sepp2k

The declaration of get_name says that the return type is string. The definition says that the return type is void.

Member Avatar for charles.dupree.37

I changed it to string but I still get the same error for get_name and get_age.

Member Avatar for mike_2000_17

The declarations are marked as const, which is correct. However, your definitions (in cpp file) are not marked const, which makes the declarations incompatible with the definitions. You need to match them exactly:

Declarations:

string get_name() const ;
int get_age() const ;

Definitions:

string person :: get_name() const // <-- notice the 'const' here.
{
    return name;  //<-- notice, you cannot modify 'name' inside this function.
}

int person :: get_age() const // <-- notice the 'const' here.
{
    return age;  //<-- notice, you cannot modify 'age' inside this function.
}

When a function is marked as const, it means that within it, the data members of the object cannot be modified. This is why I removed your code that prompts the user to enter the name or age. You need to do those things in a separate set of functions:

Declarations:

void prompt_for_name();
void prompt_for_age();

Definitions:

void person :: prompt_for_name()
{
    cout << "Please enter the name of the person ";
    getline(cin,name) ;
}
void person :: prompt_for_age()
{
    cout << "Please enter the age of the person " ;
    cin >> age ;
}

That's pretty much it. Enjoy!

Member Avatar for charles.dupree.37

Thank you very much. I really apreciate the help, hopefully I will understand it all with patience and a little help from nice people like you.

Have a nice day, C.D.

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