Updating Arrays

Quick reference

• 00:04 All right, in the last video we look at introductions to arrays.
• 00:07 In this video, I want to talk about updating an array.
• 00:09 So have got an array, you want to change something in it, how could you do that?
• 00:12 Can you do that?
• 00:13 Yes, you can.
• 00:14 So that's what we're going to talk about this video.
• 00:15 So lets get some practice.
• 00:16 For this we're going to create another one.
• 00:18 You're going to use these so often, you just really need to get into the habit
• 00:21 of creating them because like I said, you'll use them for everything.
• 00:24 So let's go string, and let's call this one toppings.
• 00:28 And this can be a new string.
• 00:31 And again, let's just put in three of these guys.
• 00:34 And let's just define it right here.
• 00:36 So we like Pepperoni.
• 00:39 Maybe some mushroom and onion, I don't know.
• 00:45 Is that a topping?
• 00:46 Sounds like it.
• 00:47 And we need a semicolon there.
• 00:49 And you notice, when I popped in the semi colon, this changed a little bit,
• 00:53 it added a bunch of space around here.
• 00:55 You can add the space, you don't have to add the space.
• 00:58 I think maybe it's a little easier to read if you have spaces in here.
• 01:02 But inside of these curly brackets, you don't have to have spaces.
• 01:06 Or you can, whichever you prefer, it's just a matter of style.
• 01:08 So all right, so then down here, we can access this guy in the normal way.
• 01:12 So let's go toppings and let's say we want the first item, we know that 0.
• 01:15 Remember the first item is always 0, it's hard to remember.
• 01:20 That makes trouble for everybody until you remember the first item is 0.
• 01:23 I'm going to keep harping on about it because it's something you're
• 01:25 going to probably forget.
• 01:26 So here we can run this and sure enough we get pepperoni.
• 01:30 What if we want to change any of these things?
• 01:33 Can we do that?
• 01:34 Yes, we can.
• 01:35 So how do we do that?
• 01:36 Well, you could see, for instance, let's change onion.
• 01:41 So that's the 0, 1, 2, the 2 with item.
• 01:46 So here we have that.
• 01:48 So let's come down here, and then I'm just going to copy this and paste it again.
• 01:54 And inside of here, let's change what the second item is.
• 01:57 So we can go toppings and then pass in that too to reference
• 02:02 that second item, 0, 1, 2, right?
• 02:06 Which is onion.
• 02:06 And here we can just change it to something else.
• 02:09 So, supreme pizza with everything, right?
• 02:14 So let's go ahead and save this and run it.
• 02:16 What do you think the outcome is going to be?
• 02:19 Well, if we run this, we see onion and
• 02:21 then supreme because it started out as onion, we printed that to the screen,
• 02:26 then we changed it to supreme, printed it again and now it's supreme.
• 02:31 So onion has just completely disappeared, right?
• 02:35 We're overriding it, it doesn't exist anymore.
• 02:38 And we can come down here again and console this out and call .length.
• 02:46 And if we save this and run it.
• 02:48 In fact, let's copy this, and do it twice.
• 02:51 So, here's the original, here's the length.
• 02:54 Then we change it, printed out, and do the length again.
• 02:57 So, let's save this and run it.
• 03:01 And we see onion.
• 03:02 The length of our array is 3, then we change it to supreme.
• 03:06 Now the length of our array is still 3.
• 03:08 So we're not adding anything to the end of this.
• 03:11 We're not adding a new thing, we're completely overriding onion with supreme.
• 03:16 So pretty simple, pretty straightforward, that's how you can update an array.
• 03:20 And you can do this for obviously everything.
• 03:23 So we did the second item, you could do the zeroth, the oneth.
• 03:29 Whatever you want,
• 03:30 you can change any position inside of your array just by adding a new item.
• 03:35 Which deletes the old thing, overwrites into the new thing, and
• 03:37 that's all there is to it.
• 03:39 So that's how we update and change an array.
• 03:41 In the next video, we'll look at appending something to the end of an array.

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