#include <stdio.h>
#include <iostream>	
using namespace std;					

// declare function 1 no argument
void myFunc_1();
// declare function 2 with an argument
void myFunc_2(int y);
// declare function 3 with an argument, returns an integer
int  myFunc_3(int z);	


int mySum1; // declare variables integer (global for this cpp file) 	
int mySum2; // when a variable is declared on the top, outside the functions
int x; // it means that all functions in this cpp-file have access to it.



int main()				
{	

	// Part I///////////////////////////////
	x = 5;
	myFunc_1();	// call function 1
	cout << mySum1 << endl; // display mySum1


	// Part II//////////////////////////////
	myFunc_2(5); // call function 2, pass in the value 5 as an argument.
	cout << mySum2 << endl; // display mySum2


	// Part III/////////////////////////////
	cout << myFunc_3(5) << endl; // display the returned value of function 3

	getchar(); // wait for a key to be pressed

	return 0;
}



void myFunc_1()	// define function 1
{
	mySum1 = x + 5;
}


void myFunc_2(int y) // define function 2 with an argument
{
	mySum2 = y + 3;
}


int myFunc_3(int z) // define function 3 with an argument, must return an integer
{

	return  z + 2;
}


/*
Learn to declare and define different functions.
and see how different functions handles the same type of task,
I have used different numbers so that you easier can tell them appart.



 Let us take a closer look at a function declaration:
----------------------------------------------------------------
 void myFunc_1();
----------------------------------------------------------------
 void		- means that the function is empty, it returnes no value

 myFunc_1	- the name of the function

 ()			- this means that there are no arguments

 ;			- end function declararion
----------------------------------------------------------------
 Decription:
 We declare our function to give the other functions access to it. 
----------------------------------------------------------------




 Let us take a closer look at a function definition:
----------------------------------------------------------------
 void myFunc_1()
 {
	mySum1 = x + 5;
 }
----------------------------------------------------------------
 void		- means that the function is empty, it returnes no value

 myFunc_1	- the name of the function

 {			- start function definition

 ()			- this means that there are no arguments

 mySum1 = x + 5;	- this is what our function does..

 }			- end function definition
----------------------------------------------------------------
 Decription:
 We must define what our function will do.
 This function takes the number 5, 
 and adds it with the value from the argument called x
 and stores the value in the variable mySum.
----------------------------------------------------------------




 Let us take a closer look at a function call:
----------------------------------------------------------------
 myFunc_1();
----------------------------------------------------------------
 myFunc_1	- the name of the function

 ()			- there is no argument passed in

 ;			- end the function call
----------------------------------------------------------------
 Decription:
 You must call your function in order to "put it to work".
----------------------------------------------------------------
*/