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‫Hello and welcome.

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‫In this lecture, we're going to be looking at these little pins and the different colors they come

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‫in and understanding that these are different data types that restrict what we can plug in to what.

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‫So let's dive right in and have a look at what I mean by a data type.

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‫So a fairly workable definition of data type is that it's how it is representing certain pieces of data

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‫in binary on your computer's memory.

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‫And but also it can just be a way of restricting what can we do with this piece of data.

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‫So it's not necessarily always about different representations.

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‫And you can think of it as the shape of the data in the sense that a square peg can't fit in a round

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‫hole.

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‫So we can't get the wrong type of data in to the wrong type of pin.

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‫So let's have a look at some examples of data types.

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‫There is the integer, which is a classic example.

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‫An integer is a whole number, so it has values like 223 -14, but not something like 1.2.

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‫That would be a float which is short for floating point number.

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‫And these are basically numbers where you have a decimal point and these numbers can be very large or

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‫very small, but they crucially are not whole numbers.

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‫They can be negative as well.

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‫And then there are strings.

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‫We've come across strings before, strings being just programmer speak for pieces of text.

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‫And it is essentially a data type.

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‫It's a way of storing pieces of text in memory so they can be anything you like.

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‫Really.

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‫Hi, Bob.

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‫You know, whatever, all these things, all these pieces of text on my screen are strings, probably

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‫somewhere in the computer's memory.

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‫And then finally there are balls which are short for booleans, and these have only two possible values,

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‫true or false?

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‫Now these data types are great, but you can't go about representing a whole game with such simple things,

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‫can you?

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‫Well, you can if you start grouping them together into things like objects.

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‫Once you group them together into an object, they start to become more meaningful.

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‫You can have an integer to represent the age, you can have a float to represent experience points,

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‫those kinds of things.

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‫And one point to note is that as well as objects, we have things in blueprint called structs.

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‫And don't get confused here.

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‫Too much struct is basically the same as an object, except that it is usually quite small and we don't

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‫use references, we just pass them around and copy them around in memory without worrying about them

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‫because they're so small.

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‫And a data type, as we said, is the shape of our data.

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‫So let's have a look at some object struct examples.

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‫So imagine we had our adventurer.

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‫Our adventurer might look a little bit like this.

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‫This is the shape of its data.

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‫It has an integer to represent its level and a float to represent its experience points.

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‫Now you might have multiple adventurer instances that are of the same adventurer class, so they have

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‫to have the same shape of data, but they don't have to have the same contents of data.

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‫You can see here the second adventurer has a level of 100 and for some reason experience points of minus

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‫five.

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‫But never mind that you could also have a different type by having a different class of object such

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‫as the player.

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‫And here you can see the shape is different.

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‫These two are the adventure and the player are non compatible types and however they do, you know,

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‫these players have different values stored in them.

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‫They have a player name, they have maybe whether they're using a controller or not as as some of the

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‫data in them.

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‫Now let's have a look at some structs that we've seen in the past.

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‫Again, remembering that structs and objects are more or less interchangeable except for their size.

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‫So the first one that we've seen quite a few times is a vector, and a vector is nothing but three floats.

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‫That's all it is an X, Y and Z float, which can be used to represent position.

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‫It can also be used to represent scale or we've used it when we've been inputting the impulse into our

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‫ADD impulse node.

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‫Another thing that we saw in passing is a rotator.

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‫Now notice this rotator is also just three floats, but that doesn't mean that these two types are compatible.

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‫We can give structs different names so that we save ourselves from accidentally using them in situations

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‫where we shouldn't.

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‫And we can put these together and create an even bigger compound structure, the transform which is

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‫the location, rotation and scale of an actor in a scene.

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‫So you can see here that this is a struct made up of other structs and you can basically nest these

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‫things as much as you like and have structs inside of objects and so on and so forth.

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‫They can get pretty complicated.

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‫So let's have a look at some objects we've seen in the past already.

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‫We've had a look at objects that are actors.

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‫We know that actors are a type of object.

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‫We've seen actors that are cubes.

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‫This is another type of object.

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‫We've seen the our projectile is a type of object as well, and it is an actor.

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‫And we've seen that we've got components on our actors, which are also types of objects.

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‫And the static component is an example of one of those.

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‫So we've got all of these and these are just made out of those basic data types down.

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‫Deep down, they might be made up of more complicated structures in the interim, but it's all about

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‫those basic data types.

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‫And so when we go and have a look at a graph like this, we can see instantly by the color that this

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‫impulse is a vector, for example, that the location, rotation and scale here are just three floating

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‫point numbers.

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‫And we can also see that this red velocity change checkbox is a boolean.

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‫It's a yes no answer.

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‫So we're starting.

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‫To understand that these are the data types that are constraining what we can plug into what.

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‫So in summary, what we've seen is that a data type is the shape of our data, that objects are just

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‫collections of data and functionality, as we've said before, that structs are objects, but usually

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‫just a little bit smaller.

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‫And that's pretty much what you need to know.

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‫I will see you in the next lecture.