// Lab 6 Lecture

// comment the examples and run individually or several at once
// by commenting out the indicated sections of code. 
// (Eclipse: ctrl+/ to comment and uncomment)
// (Code Blocks: ctrl+shift+C to comment and ctrl+shift+x to uncomment)

#include <iostream>
using namespace std;

int main()
{


// --------------------------- For Loops --------------------------------------

	// Here is a basic FOR Loop
	//
	// for ( <initialize index> ; <conditional statement> ; <increment/decrement index>)
	// {
	// 	// Statements inside the loop
	// }	


	// Like an IF statement a FOR loop will only execute the code inside of it if
	// its condition is true. However, unlike an if statement, once reaching the 
	// closing brace the FOR loop will jump back up to the top, increment/decrement
	// the index, and test its condition again. As the name describes, this ends up
	// forming a loop that will repeat until the condition is false.


	// How many times will this run? 4? 5? 6? try it.

	const int SIZE = 5;
	cout << "Entering FOR Loop 1" << endl;

	for(int i = 0; i < SIZE; i++)
	{
		cout << "value of 'i' : " << i << endl;
	}
	
	// What if our conditional statement was 'i <= SIZE'? 4? 5? 6?
	
	
// --------------- Basic For Loop to Iterate 'n' Times ------------------------

	// As you may have figured out from the above example you
	// can always use this formula to create a FOR loop that will 
	// loop 'n' number of times. 

	int n = 3;

	for(int i = 0; i < n; i++)
	{
		cout << "I will print " << n << " times" << endl;
	}

	
// ------------------------ Infinite Loops ------------------------------------

	// one thing you must always be careful when dealing with loops is 
	// the possibility of an infinite loop. Entering a number less than 
	// 10 will cause an infinite loop.
	
	// Why?
	
	int choice;
	cout << "\nEntering a number less than 10 will cause an infinite loop." << endl
		 << "Try it out! press the red box at the top of the console to kill the program." << endl;
	cin >> choice;

	for (int i = 10; i < choice; i--)
	{
		cout << "In loop 2" << endl;
	}

	
// ---------------------- How For Loop Fields Work ----------------------------

	// Yes this will actually run! Go ahead and run it. The first and third
	// field will take any single valid statement.
	
	// This loop will execute 5 times before exiting.
	// Does this shed some light on how the fields in a FOR loop work?

	int x = 0;

	for(cout << "First field\n" ; x < 5 ; cout << " Third field\n")
	{
		cout << "  Body of Loop\n";
		x++;
	}

	cout << endl;

	
// ------------------------ Nested For Loops ----------------------------------

	// FOR loops can be nested. How many times will the 'cout' execute?

	const int SIZE2 = 3;
	int count_1 = 0;
	cout << "\nEntering FOR Loop 3" << endl;

	for (int i = 0; i < SIZE2; i++)
	{
		for (int j = 0; j < SIZE2; j++)
		{
			count_1++;
			cout << "FOR loop 3 count : " << count_1 << endl;
		}
	}


// -------------------- Variable Scope In For Loops ---------------------------

	// What is the scope of variables declared in a FOR Loop?
	// If the cout below the FOR loop is uncommented you will get an error
	// because 'i's scope is limited to the the FOR loop it was created in.
	// Also, could you declare 'count_2' inside a FOR loop and still get
	// the same output? Why or why not?

	int count_2 = 0;
	int SIZE3 = 3;
	cout << "\nEntering FOR Loop 4" << endl;

	for (int i = 0; i < SIZE3; i++)
	{
		for (int j = 0; j < SIZE3; j++)
		{
			count_2++;
			cout << "FOR loop 4 count : " << count_2 << endl;
		}
	}

	//cout << i << endl;

	cout << endl;
	

// -------------------- For Loop Example ----------------------------

	// Here is an example of two nested for loops used to create ascii art.
	// I declare 2 indexes, and increment/decrement them both. 

	for (int start = 0, end = 15 ; start < end; start++, end--)
	{

		for (int i = 0; i < start; i++)
		{
			cout << " ";
		}

		for (int j = 0; j < end - start; j++)
		{
			cout << "*";
		}
		cout << endl;
	}


	return 0;
}