//***********************************************************************//

// //

// - "Talk to me like I'm a 3 year old!" Programming Lessons - //

// //

// $Author: Ben Humphrey digiben@gametutorials.com //

// //

// $Program: WhileLoop //

// //

// $Description: Shows how to use a "for loop" to cut down code //

// //

//***********************************************************************//

// This tutorial works from the ForLoop tutorial and does exactly the same

// thing, but just shows how to do it using a "while loop". Check out the

// code below:

// Import the Scanner class so we can use nextInt()

import java.util.Scanner;

// Create our class entitled "WhileLoop" for our program

public class Main

{

// Start our main() function for our program

public static void main(String[] args)

{

// We initialize 3 integer (number) variables to store

// our range. We set them equal to zero or else they

// will be some crazy number like -858993460. We could

// also have said:

// int min=0;

// int max=0;

// int i=0;

// These are the same thing--it is just cleaner the other way.

int min = 0, max = 0, i = 0;

// Now we prompt the user to input a number for the min

System.out.println("Input your first number to count from: ");

// In order to read in an integer, let's create a Scanner object

Scanner scan = new Scanner(System.in);

// Read in an integer from the user

min = scan.nextInt();

// Now we prompt the user to input a number for the max

System.out.println("Input your last number to count to: ");

// Then read in the maximum number to count to and store it in the variable "max".

max = scan.nextInt();

// Now here comes the loop.

// This is called a "while loop". You will use these a tremendous amount.

// A "while loop" is very similar to a "for loop", except there is less going on.

// "while ( <expression is true> ) do what ever is inside my brackets { }".

// That is what the "while loop" is doing. So in this case,

// "while ( min is less than or equal to max ) { print out the value of min, then add 1 to min }

// Let's say we chose 5 for min and 10 for max.

// "while ( 5 is less than or equal to 10 ) etc....

// This will print out 5, then 6, then 7, then 8, then 9, then 10 (it will print 10 because 10

// is less than or equal to 10 ). Then when min becomes 11, 11 isn't <= (less than or equal to) 10,

// so it stops and doesn't do what's in the brackets, it skips them--no more looping

while (min <= max)

{

// We print out the current value of min and skip down to a new line

System.out.println(min);

// Increment min by 1. (remember, this is the same thing as : "min = min + 1", just shorter.

min++;

// Now the code will jump back up to the while() statement and check if the

// expression is still true. If it is it will continue running the code in

// between its scope, otherwise jump down past this last bracket below.

}

}

}

///////////////////////////////////////////////////////////////////////////////

//

// * Quick Notes *

//

// Doesn't a "while loop" seem easier than a for loop? I think so, but each

// loop has its own benefits. Quickly reviewing, the demonstration we did in

// this program is actually more for "for loops"; however, just to show the

// difference of doing the same thing as the "for loop" tutorial we did it this

// way. Ideally you want to use "while loops" for loops that aren't necessarily

// dealing with numbers, but for "flags" and "states" checks. For instance,

// let's say you want to create a game and want to keep looping the game until

// the user hits 'Q' for "Quit". You could create a "flag" that is of type

// "boolean". That means that it can only be a "true" or "false" value, being

// a 1 for "true" and a 0 for "false". Something like this:

//

// boolean bNotGameOver = true;

//

// while(bNotGameOver)

// {

// bNotGameOver = HandleMainGameCode();

// }

//

// So, let's say we created a function called HandleMainGameCode() that handles

// the main game and checks input from the user. This function returns a boolean

// that tells us if the game is still going over not (e.g. the user hit 'Q').

// Initially, we set the flag "bNotGameOver" to true, telling the "while loop" to

// keep looping the game. So the HandleMainGameCode() function will keep returning

// "true" until the user hits 'Q', then it will return a "false". When the "while

// loop" checks the flag the next time it will be "false" so it will stop looping.

// See how that works? This is a more appropriate use of the "while loop".

//

// "boolean" is another useful type that you will want to use. Usually you will see

// a 'b' in front of the variable so that you know that it's type "boolean". You

// can either use the keywords "false" and "true", or just use a 1 or 0.

// Both of these are acceptable and the same meaning:

//

// boolean bFlag = 1;

// boolean bFlag = true;

//

// 1 = true and 0 = false.

//

// Try creating a program that keeps asking the user for a password and if the password

// doesn't equal the secret password keep printing an error message to the screen.

//

//

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