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Let's talk arrays or collections of stuff in Swift, let's create one var my array is equal to two square



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brackets and then whatever numbers you like in those square brackets, separated by commas.



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So if I go to the next line and I type my ah, let's see what kind of thing it is.



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My array of integers, so an array is a collection of the same kind of thing, in this case integers,



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that's as big or as small as you want it to be, but it's a way of stacking together similar types of



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variables that you don't want to create lots of variables for, obviously.



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The interesting thing actually about arrays is that they are stored sequentially in memory with most



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languages.



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So if I want the value five and six, they actually sit next to each other, at least logically in the



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memory, perhaps not physically.



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I haven't looked into it that far, but they sit next to each other as far as memory addresses go.



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OK, so that is an array, a collection of like minded items.



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Now we can explicitly tell the system what kind of array we want so we can have vah and we can tell



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it.



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I want right now an array of type string and then I'm going to give it an array of strings.



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Just two of them.



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Hi there.



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So there are two strings in that array, and we've told the system this is an array of strings, of



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course, we could potentially do the same up top here.



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We say this is an array of, you guessed it, integers.



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And as long as it's getting what it wants, then we're all good if I put five point eight in here.



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We should get a nice red arrow because I've tried to insert a double rainbow, five point eight is not



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an integer.



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Now, some languages would actually take that five point eight, drop the point eight and just give



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you five, which is an awful idea as far as languages go.



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Okay, so what else have we got on my notes here via Mayan's?



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This is another way of declaring your array is equal to an array of integers.



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Open and closed brackets, so in this case, there are zero elements in this array which are saying



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just initialize it so it's ready for me to use because I don't have anything to put inside it just yet.



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Now, how do you put things inside?



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Well, we go to my aunt's dot and you'll notice there are lots of functions we can use here.



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We can append the number eight.



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So now it adds the number eight.



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We can have my aunts dot append the number two or one.



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And if we run that.



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We should get nothing.



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Eight and then eight and one as the elements of this particular array.



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How do we access the items in the array?



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Well, that is very straightforward.



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We have my int.



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We open the square brackets and we give it the index, so the first element in an array is always element



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zero.



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Everything in programming is zero based indexing.



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You start counting at zero.



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So if I run, this zero will be the element of eight.



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Now, of course, that doesn't spit out an array that's giving us an integer because we've gone away,



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we've dove into the array already and we're pulling out that individual item, whatever type it is,



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in this case, an integer.



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Right.



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So your homework, nice and simple, perhaps.



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Create a three element array of numbers, multiply all of them.



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Now the tasks are starting to get a little bit harder.



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If you're new to all of this, so sit down and just think about how you'd go through this.



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Don't worry about the code.



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What I'd like you to do is think conceptually about it, writing a piece of paper on your iPad, on



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your phone, how you think these should be laid out.



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A lot of code, a lot of problems that we need to solve in code are solved by logical thinking, not



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by knowing code.



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Yes, it's partly knowing code, but most of the work is done in just thinking logically, first of



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all.



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So give that a go and I'll see you in the next one.