'variableFlag' does not name a type

IDE that I'm using : Code::Blocks 16.01|Compiler that I'm using : MingGW GCC 6.3.0

Error(s):

Build Messages: v1 - Arrays\main.cpp|8|error: 'variableFlag' does not name a type|

My Objective(s): Want to set a global variable : variableFlag that's shared with all the *.CPP programs. I want to set it to a default setting of 0, or 1. If it's set to 0, I don't want to display the if statement in function : void print(int input) in mainLibrary.cpp. If it's set to 1, then display the if statement within the function.

mainLibrary.cpp

#include <iostream>
#include "mainLibrary.h"
#include <string>
using namespace std;

//int variableFlag;
//variableFlag = 0;

void asciiTable()
{
    for (int id = 0; id < 256; id++)
    {
        char test = id;
        cout << "ASCII CODE : " << id << " = " << test << endl;;
    }
}

void dataTypesSize()
{
    cout << "Size of char      : " << sizeof(char) << endl;
    cout << "Size of int       : " << sizeof(int) << endl;
    cout << "Size of short int : " << sizeof(short int) << endl;
    cout << "Size of long int  : " << sizeof(long int) << endl;
    cout << "Size of float     : " << sizeof(float) << endl;
    cout << "Size of double    : " << sizeof(double) << endl;
    cout << "Size of wchar_t   : " << sizeof(wchar_t) << endl;
}

void print(int input)
{

    if (variableFlag==1)
    {
        cout << "\nprint(int input)" << endl;
    }

    cout << input << endl;
}

void print(long input)
{
//    cout << "\nprint(long input)" << endl;
    cout << input << endl;
}

void print(double input)
{
//    cout << "\nprint(double input)" << endl;
    cout << input << endl;
}

void print(const char* input)
{
//    cout << "\nprint(char input)" << endl;
    cout << input << endl;
}

void print(string input)
{
//    cout << "\nprint(string input)" << endl;
    cout << input << endl;
}

void printLine(const char* input)
{
    cout << input;
}

void printLine(string input)
{
    cout << input;
}

void printLine(double input)
{
    cout << input;
}

void variableSwap(int &input1, int &input2)
{
    int temp = input1;
    input1 = input2;
    input2 = temp;
}

void variableSwap(double &input1, double &input2)
{
    double temp = input1;
    input1 = input2;
    input2 = temp;
}

void variableSwap(string &input1,string &input2)
{
    string temp = input1;
    input1 = input2;
    input2 = temp;
}

mainLibrary.h

#include <iostream>
#include <string>

using namespace std;

#ifndef ASCIITABLE_H_INCLUDED
#define ASCIITABLE_H_INCLUDED

extern int variableFlag;
//int variableFlag;

void asciiTable();
void dataTypesSize();
void print(int input);
void print(long input);
void print(double input);
void print(const char* input);
void print(string input);
void printLine(double input);
void printLine(const char* input);
void printLine(string input);
void variableSwap(int &input1,int &input2);
void variableSwap(double &input1,double &input2);
void variableSwap(string &input1,string &input2);

#endif // ASCIITABLE_H_INCLUDED

main.cpp

#include <iostream>
#include "..\Library\mainLibrary.h"
#include <string>

using namespace std;

//int variableFlag;
variableFlag = 0;

int main()
{
    asciiTable();
    dataTypesSize();
    string names[10]; //Initializes names array as 0-9 which has a total of 10 places;

    print ("Welcome to : mainLibray 1.0");
    print ("");
    print ("This program will display all the data in 'names' array:");
    print ("");
    print ("");

    for (int id = 0; id < 10; id++)
    {

        names[id] = id * 2 + 65;
    }

    for (int id = 0; id < 10; id++)
    {
        cout << "id : " << id << " = " << names[id] << "\n";
//        cout << id << "\n";
    }

    int cnt = 1.1;
    cout << cnt << endl;
//    int cnt = 1;

    printLine("My ");printLine("name ");printLine("is ");printLine("Dusty!");cout << endl;//printLine(cnt);

    print(200303.112);

    int a = 1;
    int b = 2;
    printLine("a = ");printLine(a);printLine(", b = ");print(b);
    variableSwap(a,b);
    printLine("a = ");printLine(a);printLine(", b = ");print(b);

    double x = 1.1112;
    double y = 2.2223;
    printLine("x = ");printLine(x);printLine(", y = ");print(y);
    variableSwap(x,y);
    printLine("x = ");printLine(x);printLine(", y = ");print(y);

    string n1 = "Polar Bear";
    string n2 = "White Eagle";
    printLine("n1 = ");printLine(n1);printLine(", n2 = ");print(n2);
    variableSwap(n1,n2);
    printLine("n1 = ");printLine(n1);printLine(", n2 = ");print(n2);

    return 0;
}