// LOOPS

// Loops are ways to run certain lines of code until a
//   certain condition is met.
// These conditions are often reaching the end of a predefined sequence.
// To do this loops require creating a variable that
//   will explain the length of the loop.
// Each loop has a specific syntax to differentiate itself
//   from the others and work in different ways.
// These syntax explain how the variables are defined.

// There are several types of loops, including:

// FOR
// FOR IN
// WHILE

// A FOR loop is an easy way to have code move forward or backward.
// A for loop has three parts to it before you get to its statement.
//   * initial expression
//   * condition
//   * increment expression

// Syntax:

// for(inintialExpression; condition; incrementExpression)

// The INITIAL EXPRESSION is the starting point for your loop.
//   This is often represented as a variable "i".
//   You must assign this variable a value to start.

// The CONDITION tells your code how long it should run.
//   Wherever your initial expression starts, this will be its destination.

// The INCREMENT EXPRESSION tells your code how it should progress.
//   This is where the increment and decrement operators shine.

// Example for loop:

for(var i = 0; i < 10; i++) {return i;}

// In that case, the code would begin at 0 and run until 9.
// It would return each number between 0 and 9.
// You could also go from 9 to 0 by simply swapping the initial expression
//   value and condition value, and having the increment expression DEcrement.
// For loops are very useful for things like arrays, but do not
//   work on normal objects.
// For example, you could loop through an array using bracket notation.
// In the case of the previous loop, it would be like returning array[i].
// This would not work with an object because objects have keys instead
//   of index numbers.



// A FOR IN loop is similar to a for loop, but it can work with objects.
// Its syntax much simpler than a simple for loop.
//   You start again by calling for
//   Then in parenthesis give a variable to represent the objects properties
//   Then say "in"
//   Then call the object you want to loop through

// Syntax:

// for(propertyVariable in object) {code to run}

// Example for/in loop:

var obj = {key1:1, key2:2, key3:3}
for(i in obj) {return obj[i]} // returns all values of obj



// A WHILE loop will loop WHILE a set condition is still true
// This is similar to a for loop, but with a looser syntax.
//   You call WHILE,
//   Put a condition in the parenthesis
//   The condition should contain a variable that will change
//   Variables must be assigned before the loop runs
//   Then the code you put in curly braces will run
//     as long as the condition is true
//   For this loop you must put the increment INSIDE the curly braces.

// Syntax:

// while(condition) {code to run}

// Example of while loop:

var n = 10;
while(n > 0) {n--; return n;} // returns 9 through 0