Commit 768590d

- https://en.wikipedia.org/wiki/Object-oriented_programming

- https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/this

- https://developer.mozilla.org/en-US/docs/Glossary/Scope

- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions

And just for fun ... https://www.freecodecamp.com/challenges/sum-all-numbers-in-a-range

Loops practice - https://www.freecodecamp.com/challenges/iterate-with-javascript-for-loops

1.

We learned a little bit about callbacks in JS. A callback is simply a function passed to another function that gets executed (run) after a potentially long running operation has completed. There is another function called `setTimeout` that will wait a specified period of time and then execute a function. For example:

```

function doIt() {

console.log('I am done');

}

setTimeout(doIt, 5000)

```

If you run the above code it will wait 5 seconds and print `I am done`. Please read something about setTimeout on MDN. The first argument to the `setTimeout` call is the callback (`doIt`)

You must write a function that takes 4 arguments.

- A start value

- An end value

- A callback to call if the number is divisible by 3

- A callback to use if the number is divisible by 5

The function should generate an array containing values from start value to end value (inclusive).

Then the function should itereate over the array and call the second argument if the array value is divisible by 3

The function should call the second argument if the array value is divisible by 5

Both functions should be called if the array value is divisible by both 3 and 5

```

THIS IS FAKE CODE

function threeFive(startIndex, stopIndex, threeCallback, fiveCallback) {

// make array

// start at beginning of array and check if you should call threeCallback or fiveCallback or go on to next

}

threeFive(10, 15, sayThree, sayFive);

// Should create an array [10,11,12,13,14,15]

// and call sayFive, sayThree, sayThree, sayFive - please make sure you see why these calls are made before you start coding

```

2.

Please solve this problem using:

1. A for loop

2. A while loop

3. A do loop

3.

Some practice with objects

4.

Nested loops

5.

We did some work with arrays - `var arr = [1,2,3]`

We can also nest arrays inside arrays like this `var arr2d = [[1,2], [3,4], [5,6]]` (for math people you can think of this as a matrix)

How would you print all the items of an array with 3 dimensions?

How about with K dimensions?

What if you didn't know how deep the array was nested? (You don't have to write code for this but think about it)

6.

Here are two functions that look like they do the something similar but they print different results. Please explain what's going on here.

If you are confused please run the code and then consult the Google for "javascript pass by value pass by reference"

7.

Next time we're going to cover the following Javascript topics:

- Immediately Invoked Function Execution (IIFE) and anonymous functions

- The this variable

- Scope and closures

- Promises (callbacks part 2)

- Using APIs

Please read up on these topics