Multi-Dimensional Arrays

Quick reference

• 00:04 In this video, I want to talk about multi-dimensional arrays.
• 00:07 So we already started talking about arrays in the last video.
• 00:10 And we put a bunch of strings into our array.
• 00:13 John, Bill, Mary, and Tim.
• 00:14 Now you can put all kinds of other things in your array,
• 00:17 it really doesn't matter what you put in there.
• 00:19 We can put in an integer, 41.
• 00:22 We can put 12.99.
• 00:24 So if we change this to 5, save it and run it, we get 12.99.
• 00:31 If we add -1, 11.99.
• 00:34 So this is a number, it's a float and we can do math on it.
• 00:38 We could change this to 0, and go plus 1.
• 00:43 And of course, we should get an error here because we already
• 00:46 understand we can't add a number and a string.
• 00:48 They're two different data types.
• 00:49 But anyway, get rid of all of that.
• 00:52 So we can add numbers, we can add other variables.
• 00:55 So we can call name = Susie, and we could put name in there.
• 01:01 So now 0, 1, 2, 3, 4, 5, 6,
• 01:06 if we output the sixth item, we get Susie.
• 01:11 So strings, numbers, floats, integers, other variables.
• 01:15 Now what I really want to talk about in this video multi-dimensional arrays.
• 01:19 We can put strings, we can put numbers, we can put other variables, and
• 01:23 we can put other arrays.
• 01:26 This is really going to blow your mind.
• 01:27 So 1, 2, 3, Josh,
• 01:32 Tina, whatever.
• 01:36 So now, if we save this thing and
• 01:38 let's just print out our whole array and see what we've got here.
• 01:43 We see we have John, Bill, Mary, Tim 41, 12.99 and Susie.
• 01:48 Then we've also got this 1, 2, 3, Josh and Tina.
• 01:52 So what's going on here let's clear the screen.
• 01:54 Now let's call, let's see we've got 1, 2, 3, 4, 5, 6, 7, 8.
• 02:02 This whole thing is the eighth item in our array, or in this case number seven,
• 02:07 item number seven.
• 02:08 So if we save this and run it, we get 1, 2, 3, Josh and Tina.
• 02:12 So how do we access something in our array of arrays here?
• 02:17 Well, we want something from item number seven which is this array and
• 02:22 then we want the, let's say zeroth item from that.
• 02:26 So if we save this and run it, so the zeroth item is 1, 0, 1, 2, 3.
• 02:32 Let's see what the third item is our brackets disappeared.
• 02:36 So we save this and run it.
• 02:38 We get Josh.
• 02:38 So this is a multi-dimensional array.
• 02:42 It's an array with other arrays in it.
• 02:44 And like I said, you can put all kinds of stuff in arrays including other arrays,
• 02:48 including other objects, methods, all kinds of things.
• 02:51 Hashes we can do I believe, we'll get into that much later on.
• 02:54 But those are arrays, those are multidimensional arrays.
• 02:57 The first time round,
• 02:58 it's kind of tricky to think about an array inside of an array.
• 03:01 You gotta kind of work it through in your brain a little bit say, okay,
• 03:04 that's how it works.
• 03:05 But pretty easy, just name the item, this is the seventh item.
• 03:09 This whole array is the seventh item.
• 03:11 And inside of that we just call like we would a regular array.
• 03:14 So inside of this array we could do another array, and
• 03:17 we just keep adding onto it if we wanted to.
• 03:21 So those are arrays.
• 03:23 In the next video, we're going to start talking about loops,
• 03:26 specifically the while loop.

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