CodeBloks C++ Error: Was not declared in the scope

Question

Hey guys I'm trying to learn C++ and I was doing pretty well until I hit this wall..

I am getting two errors: error: 'enter' was not declared in this scope error: 'Satisfies' was not declared in this scope|

Here is my file. Why is that?

include <iostream>

using namespace std;

int main() {
    while (1){
        char menu;
        cin>>menu;
        switch (menu){
            case 1: Enter(); break;
            case 2: Satisfies(); break;
            case 3: break;
            };
    };
}

int Enter(){
    return 0;
}

int Satisfies(){
    return 0;
}

Function calls need `()`, eg `Enter();`. Also free functions must be declared before they are used, so above `int main()` — lcs, Nov 20 '14 at 16:48
It's hard to tell with that formatting. But for starters move your helper functions above the main, or declare their prototypes above main. — maxywb, Nov 20 '14 at 16:49

score 2 · Answer 1 · answered Nov 20 '14 at 16:49

2

You have to declare the functions before their usage for example before main and use the correct syntax of calling functions.

For example

//...
int Enter(){ return 0; }

int Satisfies(){ return 0; }
//...
int main()
{
//...
case 1:
   Enter();
//...

answered Nov 20 '14 at 16:49

Vlad from Moscow

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score 1 · Answer 2 · edited May 23 '17 at 11:59

You need to declare the functions before they are used. So put this above main:

int Enter();
int Satisfies();

You can leave the definitions (the bit that actually contains the code to run when the function is called) where they are. Or you can just move those functions above main, since a function definition is also a declaration.

The compiler needs to see these bits before it tries to call the function, so that it can know what arguments it needs, and what will be returned.

See this question.

score 0 · Answer 3 · answered Nov 20 '14 at 16:58

You need to declare (or declare and definite) a function before you use it. And you need to make function calls with (). Like Enter() and Satisfied(). If you want to learn good programming and C coding and then go to C++ read "C for Dummies" by Dan Godkin. My favourite coding book.

You have 3 ways to do this and fix your code:

1. Write prototy definitions:

#include <iostram>

int Enter();
int Satisfies();


using namespace std;

int main() 
{  
   //bla
}

int Enter(){ return 0; }
int Satisfies(){ return 0; }

2. Make a function.h file and put the declarations there. Save it in the same folder as the c / cpp file

then include in your code

#include "function.h"

3 Put your functions in order of execution in the c/cpp file. A function must be declared before it is used. Example:

void Enter()
{
  //bla
}

void Satisfied()
{
  //blub
}

int main() 
{
 Enter();
 Satisfied();
}

More tricky example, when a function (Satisfied) uses an other function (Enter) the Enter function must be declared before the Satisfied function:

void Enter()
{
  //bla
}

void Satisfied()
{
  //blubb
  Enter(); //now Enter must be declared before is Satisfied() is defined, so it must be "over" it in the source like in this example
}

int main() 
{
 Enter();
 Satisfied();
}

score 0 · Answer 4 · answered Nov 20 '14 at 16:59

Function call need to have () after the function name doesn't matter whether it take any parameter or not. Plus you need to define function header before main()

include <iostream>
using namespace std;
int Enter();
int Satisfies();

int main() {
    while (1){
        char menu;
        cin>>menu;
        switch (menu){
            case 1: Enter(); 
                break;
            case 2: Satisfies(); 
                break;
            case 3: 
                break;
        };
    };
}

int Enter(){
    return 0;
}

int Satisfies(){
    return 0;
}

CodeBloks C++ Error: Was not declared in the scope

4 Answers4