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So now let's look at some selected methods of a race and we just picked a few.

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There are a lot more.

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And if you look at the Mozilla documentation, you'll find out about all of them.

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So two of the most popular methods for the arrays are push and pop.

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And what push does is pushes the value onto an array and pop or pop the value off the last value.

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So if we push 25 on and we pop, we'll get 25 back.

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And then there's some that may seem a little familiar from strings.

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For example, there's an index of where is the index of a value of 25 for the last index of you're going

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to reverse an array to turn it from front to back.

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Slice is a lot like the string slice.

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So it gets the values starting at position two and then prior to index four.

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And then you can do sorting with an array.

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And this is very important.

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So if you have an array of strings, you can use this method without doing anything else.

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So in my earlier example, we have an array of names.

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You can sort them alphabetically, but if you have numbers or something more complicated, you need

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to provide a function to do the sorting.

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And we'll talk about that in a later section.

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OK, I'm back in this array program that we started in the previous section, so it's going to come

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in kind of handy here.

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So let's do a couple of methods.

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So if I say push, I will say my array that push 100 and then let's log that out.

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And then I'm going to pop that out as well.

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So let's just repeat this, except for the very first thing I'm going to put on the log is the pop.

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So it's kind of Poppit, it's going to put out there and it's going to turn out the one.

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Let's come on a few things out.

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All right, so the first thing we do is we pushed 100 onto the array and now it's here at the end and

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then we popped it and you can see we got 100 off and now they're raised back to five in length.

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And if we keep popping, we're going to pop things off with pop more than we can get.

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But you can see we're getting one hundred eight six five four two two is the last thing, right?

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I don't think I'd consider it loud enough.

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I wanted to do it a couple more times just to see what happens when the array is empty.

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So when it's empty, we get undefined.

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So I said, OK, it's undefined, it's empty.

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Empty array in its length is zero.

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So no matter how many times you try to pop into your head, you're not going to get anything out of

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it, but you can then push again.

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Another problem there, if I take this push and put it down in here, we can push that that 100 back

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onto the tray.

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And so then we got one hundred off at the end.

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All right, let's try something else.

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At these out, we can try the index of.

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And we know we have an index of, say, number five.

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So we can say cancel that log, my array index of and you can see like some of the other ones, it has

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a search element and a from index.

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Where do you want to start searching?

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So we'll just say five won't specify from index.

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So we've got the number two, and if we scroll back up here, we can see that the five is a position

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to zero one to.

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So that's how I found it.

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How about the reverse?

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We won't worry about the last index except for right now.

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So if I say console that, log my array dot reverse.

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And so eight, six, five, four, two.

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In the era, did it change the era, let's add that to the log.

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Yeah, it did.

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We have to be careful about which ones are using some of these will return a new array and some of them

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will change the array itself, like push changes the array.

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So one last one will try is the sort so we can use the sort method, but it's going to need something

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to actually make it sort correctly.

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So let me demonstrate.

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How can so it looks right.

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So I'm going to say my array and I'm going to put in some strings and I'll say a.

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I start with something like lower

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Cafcass square brackets.

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And then, as I says, you you a with quotes and we'll leave it there.

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So now I say, Meyera, that sort,

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and we want to put it up.

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So we've got our very nicely sorted ways and then the ends and the has been used and disease.

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So we run into problems though is if we have numbers in here, because numbers in the sort of algorithm

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are treated like strings.

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And so sorting numbers is going to work very well demonstrated.

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Versus changes back to a number array.

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We'll say one thousand or one hundred thirty ten.

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Fifteen hundred, three hundred and thirty three.

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Twelve.

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OK, so let's see what happens when we start that array.

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So now we get an order that we're not expecting because it's sought by the as if it's a string, so

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sorting based upon the first character going left to right, so says, OK, the ones come first and

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then the threes.

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But you see the one zero comes before one too, which comes before one five.

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So the numeric value of the number doesn't matter.

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It's only the string.

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So the sort numbers we have to do something more or in the next two sections we're talking about the

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spread operator and de structuring arrays and this is a little more of an advanced topic.

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So you could skip and come back to it or you could go through it now and come back to it later.

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But it's something you definitely need to practice.