C++ Question
not declare in scope when compiled g++
This is my A.h file
class A
{
public:
void menuChoice();
void displaystartingMenu(); //EDIT
};
This is my A.cpp file
#include "A.h"
void displaystartingMenu()
{
cout<<"Please enter your choice:";
}
void A::menuChoice()
{
displaystartingMenu();
cout<<"Hello"<<endl;
}
int main()
{
A a;
a.menuChoice();
}
i tried to put
void menuChoice();
on the top of my cpp file but it still won't compile . it gives me error
In function ‘int main()’: A.cpp:112:13: error: ‘menuChoice’ was not declared in this scope menuChoice();
How do I compile : g++ A.cpp A.h
By right I don't need to even declare the function of top of the cpp because I have already declare it in my header file and I have included in my .cpp. What went wrong here?
EDIT:
Error :
In function `A::menuChoice()':
A.cpp:(.text+0x229): undefined reference to `A::displaystartingMenu()'
Answer
Option 1: Make an A instance and call that instance's menuChoice method:
#include <iostream>
class A {
public:
void menuChoice();
};
void A::menuChoice() {
std::cout << "Hello" << std::endl;
}
int main() {
A a;
a.menuChoice();
return 0;
}
Option 2: Make menuChoice a static method and call it as A::menuChoice:
#include <iostream>
class A {
public:
static void menuChoice();
};
void A::menuChoice() {
std::cout << "Hello" << std::endl;
}
int main() {
A::menuChoice();
return 0;
}
Edit: Addressing the new problem, when you tried to define A::displaystartingMenu you wrote:
void displaystartingMenu() {
// ...
}
It must be defined like this:
void A::displaystartingMenu() {
// ...
}
Source (Stackoverflow)