How do I cout each function? I declared it in the scope, I don't know why it won't cout anything.

[Catungal]

#include <iostream>
using namespace std;

	int smaller (int a, int b) // return the smaller of a and b (if they are equal then just return that value)
	{
			if (a < b) // if a is less than b, then return a
			{
				return a; // return value of a
					cout << a << endl;
			}
				else if (b < a) // if b is less than a, then return b
				{
					return b; // return value of b
						cout << b << endl;
				}
					else //otherwise, if a is not smaller and b is not smaller, then return a or b ...
					{
						return a; // return value of a since it is equal to b
							cout << a << endl;
					}							
								int smallerOfAB = smaller(a, b); // stores the smaller value of a and b into smallerOfAB
	}

	int bigger (int a, int b) // return the bigger of a and b (if they are equal then just return that value)
	{
			if (a > b) // if a is greater than b, then return a
			{
				return a;
			}
				else if (b > a) // if b is greater than a, then return b
				{
					return b;
				}
					else // otherwise, if a is not bigger and b is not bigger, then print ...
					{
						return a; // return value of a since it is equal to b
					} 
							cout << endl;
								
								int biggerOfAB = bigger(a, b); // stores the bigger value of a and b into BiggerOfAB

									cout << biggerOfAB << endl;
	}

	int smallest (int a, int b, int c) // return the smallest of a, b, and c
	{
		smaller(a, b);
			int smallerOfAB = smaller(a, b);

		smaller(smallerOfAB, c);
			return smaller(smallerOfAB, c);
				int smallestOfABC = smaller (smallerOfAB, c);
	}

	int biggest (int a, int b, int c) // return the smallest of a, b, and c
	{	
		bigger(a, b);
			int biggerOfAB = smaller(a, b);

		bigger(biggerOfAB, c);
			return bigger(biggerOfAB, c);
				int biggestOfABC = bigger(biggerOfAB, c);
	}

	int middle (int a, int b, int c) // return the middle value of a, b, and c
	{
		smaller (a, b);
			int biggerOfAB = smaller (a, b);

		smaller (b, c);
			int biggerOfBC = smaller (b, c);

		smaller (a, c);
			int biggerOfAC = smaller (a, c);

		biggest (biggerOfAB, biggerOfBC, biggerOfAC);
			return (biggerOfAB, biggerOfBC, biggerOfAC);
	}

	int main () 
	{
		int a, b, c;
		smaller (1, 2);
		cout << a << b;
		bigger (1, 2);
		smallest (1, 2, 3);
		biggest (1, 2, 3);
		middle (1, 2, 3);
			return 0;
	}

[xismn]

The variables you're instantiating on line 82 - are those supposed to be arguments you pass to your functions? Because you're not passing them to your functions, and you haven't initialized them either. The smaller, bigger, smallest, biggest and middle functions all return a value, so just print them like so:

std::cout << smaller(1, 2) << std::endl;

[Thomas1965]

Statements after a return won't be executed.

if (a < b) // if a is less than b, then return a
{
  return a; // return value of a
  cout << a << endl;
}