#include <iostream>
#include <string>
using namespace std;

//basic "void" function.
//void means this doesn't give you anything, or return anything
//This function just does something
void someFunction()
{
	cout << "Welcom to this cool function" << endl;
	for (int i = 1; i <= 10; i++)
	{
		cout << i << ", ";
	}
	cout << "Done!" << endl;
}

//This void function takes one integer n as input
void printUpTo(int n)
{
	for (int i = 1; i <= n; i++)
	{
		cout << i << ", ";
	}
	cout << "Whoo! done!" << endl;
}

//This void function takes in 2 parameters
//This function prints numbers from
//value 'start' to value 'end'
void printFrom(int start, int end)
{
	/*
	for (int i = start; i <= end; i++)
	{
		cout << i << ", ";
	}
	cout << endl;
	*/
	int i = start;
	while (i <= end)
	{
		cout << i << ", ";
		i++;
	}
	cout << endl;
}

//Parameter list my be arbitrily diverse,
//including strings, ints, or whatever.
void annoyingKid(string sentence, int numTimes)
{
	for (int i = 0; i < numTimes; i++)
	{
		cout << sentence << endl;
	}
}

//this function returns an 'int'
int add(int a, int b)
{
	int total = a + b;
	return total;
}

//Compute the sum of integers from a to b.
int sumTotal(int a, int b)
{
	int total = 0;
	for (int i = a; i <= b; i++)
	{
		total = total + i;
	}
	return total;
}

//Type 'bool' is short for boolean.
//boolean variables have value either 'true' or 'false'.
bool greater(double x, double y)
{
	if (x > y)
		return true;
	else
		return false;
}

int main()
{


	//void function, no parameters
	someFunction();
	someFunction();
	someFunction();

	//void function, but with a parameter
	printUpTo(5);
	printUpTo(10);
	printUpTo(20);

	//another void function, but with 2 parameters
	printFrom(5, 15);

	//You may pass variables as well
	int x = 3;
	int y = 7;
	printFrom(x, y);

	//May pass multiple parameters of different types
	string phrase = "Are we there yet?";
	int numReps = 5;
	annoyingKid(phrase, numReps);
	annoyingKid("Mom lets us do that!", 3);


	//Now a function that returns a value
	cout << add(5, 3) << endl; // 8
	int num1 = 13;
	int num2 = 20;
	cout << add(num1, num2) << endl; //33
	int sum = add(14, 35);
	cout << sum << endl;  // 49


	//Challenge:
	cout << sumTotal(10, 35) << endl; //10+11+12+...+35
	cout << sumTotal(5, 12) << endl;
	cout << sumTotal(72, 93) << endl;

	//Implement a function 'greater' that returns true if
	//first parameter is great than second, false if not.
	double number1, number2;
	cout << "enter 2 numbers" << endl;
	cin >> number1;
	cin >> number2;

	if (greater(number1, number2))
	{
		cout << number1 << " is greater " << endl;
	}
	else
	{
		cout << number1 << " is not greater" << endl;
	}

	//Next up... read about pass by reference!

	return 0;
}