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In this lecture, we're going to finish off our script to objects so that they also hold the answers

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to our questions.

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And in the process, we're going to learn a little bit more about arrays.

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So here we are in one of our scripts or objects which is currently only holding the question text.

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So let's have a think about how we're going to store the answers to our quiz.

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Well, on our canvas we have four buttons, so one for each answer.

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So your first instinct might be to store each answer as its own unique string.

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This is a perfectly fine approach, but it is a little bit cumbersome and not very flexible.

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So rather than doing this way, what we're instead going to do is use something called an array.

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So what is an array?

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Well, you can think of them as a grouping of multiple variables of the same type.

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So if we think about this in terms of our answers, rather than having four unique string variables,

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we can have a single array of strings.

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Now, when we group variables into an array, each item that we store in that array is called an element,

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and each element can be accessed within the array by its index number.

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So they're very easy to work with, especially when we start looking at looping through them.

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Now one thing to note about arrays and a lot of things in computers, in fact, is that counting starts

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at zero.

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So the first element in an array is element zero.

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And this is initially quite confusing if you're not used to this zero indexing that computers use,

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but with a little bit of time and a little bit of practice, this will soon become second nature to

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you.

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So let's look at an example of what an array might look like.

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Well, here we have an array of odd numbered integers, and specifically we've got the first five odd

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numbers.

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Now, just like any other variable, we have declared the type at the front.

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So this is storing integer values.

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But notice these brackets after the type declaration, these brackets indicate that we're now dealing

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with an array of integers rather than just a single integer.

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We have our name of our variable just like any other.

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So we've called this one the odd numbers and we've initialized it with the first five odd numbers.

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So notice that we've used these braces on either side and then we have five elements inside this.

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But because we start counting at zero, each element within that would have an index of zero, one,

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two, three and four.

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And again, this can be a little bit confusing if you're not used to this zero indexing, but please

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do trust me on this, that the more that you work with them, the easier this does become.

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Now, this isn't the only way to initialize an array, so we don't necessarily always know what values

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we want to place in the array.

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And when that happens, what we can do is we can initialize it like this.

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So the front is exactly the same.

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We've still got an array of integers called odd numbers, but now we're initializing it as a new array

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of integers with a size of five.

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So we're saying that this array will have five slots, if you like, five elements contained within

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it.

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And then later on we might access one of those elements by its index number and then change that.

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The same we might change a regular old integer.

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So let's jump over into our script object now and see these arrays in action.

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Now the answers to all questions are generally going to be strings and so make it into an array.

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I just need to open some brackets.

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I'm then going to give my variable a name.

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So let's call this the answers.

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And because I don't necessarily know what the answers are going to be ahead of time, all I know is

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that each question will have four answers.

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I'm going to initialize my array by saying that it's equal to a new string array.

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So with the brackets open there and within these brackets, I'm going to put the number four.

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So there's going to be four elements to my array.

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The next step now we've set up the core of our variable is to think about the access level that it needs.

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So just like our question, we're going to want to be able to change them in the inspector, but we

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don't want to be able to change them from outside the script object.

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So for this, I think a serialized field is again a very good choice for the access.

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And if we save our script table object and jump back into unity, we'll see that we now have this rolled

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up option for answers in our script or objects so we can unroll this and we have four elements and notice

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the element start counting from zero up to three and we can go ahead and then fill in the potential

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answers to our question.

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Now this question has some answers attached to it.

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We now need to know which one is the correct one.

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So now we're going to need another variable attached to our script to object to tell us which element

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of this array holds the correct answer.

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So back over into our script will object.

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Let's again create another new variable and this time it's going to hold the index number for our answer.

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So before you just follow along with me, see if you can write this variable for yourself and this isn't

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a full challenge.

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So I'll just give you a moment to think before carrying on.

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Okay.

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So this is going to be a integer type because we're asking for an index number for our array and I'm

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going to name this the correct answer index.

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Now we need a way of setting this in the inspector and we still don't want this to be public to other

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scripts in our game.

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So let's again use a serialized field and that will now give us a way of storing the index to the correct

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answer.

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So if we start, say, the number three as our correct answer index, this would relate to the fourth

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element of our answers array because again, remember that this starts counting at zero.

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Next, we want to go ahead and finish off our script object.

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So just like with our public getter method for our question, we're going to need a getter method for

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the correct answer index and another getter method to get an answer at a specific index.

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And I think that brings us nicely on to your challenge.

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I want you to create two more getter methods.

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The first one is going to be called Get Correct Answer Index.

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So think about the access level of the method, the return type of the method and what variable it's

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actually going to return.

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And the second one, which is a little bit more complicated but not by much, is going to be called

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get answer.

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And I say this one is a little bit more complex because this one is also going to accept a parameter

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of type int, which is going to be called index, so that when you use this method from outside the

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script, you can pass in the index for the answer that you want and get that particular answer out of

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our answers array.

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So pause the video now and give that one a go.

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Okay.

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Welcome back.

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So hopefully you got on well with both of those, but don't worry too much if you struggled with the

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second one.

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Let's go through both of them now for the first one to return the correct answer index.

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Our getter methods are always going to be public and in this case it's going to return an integer.

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And we said that we were going to call this one get correct answer index.

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I know this one is going to do is return the correct answer index.

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So congratulations if you manage to do that first one without any problems.

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And now let's look at the second one.

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And I'm actually going to put this one just above.

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It doesn't really matter where you place it.

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So if you put it below, then that's absolutely fine as well.

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And again, it's a getter method, so it's going to have to be public so other scripts can use it and

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it's going to return a string.

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And this is just a single string, so not an array of strings.

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And we said this was going to be called get answer.

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We also said that this was going to accept a parameter of type int called index and for this one we

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want to return the answers and the index that we specified.

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So what this method is doing is it's passing in an index that we want to use and then just returning

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the answer at that given index.

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And if we go ahead and save our script and head back over into unity, we now have our complete script

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for object.

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We have space for the question.

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We have space for all four answers, and we can also specify the index for the correct answer.

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So in this case, the correct index is zero, but we can place any number in there that we like.

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So it might be that we need the correct answer index to be two.

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Now, one thing to be very careful of going forward is that this correct answer index is currently unconstrained.

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So we can have the correct answer of -56 or the correct answer of 54, and we should probably try and

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prevent that.

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So the designer doesn't accidentally put in something crazy, but for now, we'll leave it as it is,

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and we may come to fix that in a later lecture.

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For now, though, I think we've spent long enough on our script to object, and it's about time we

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started actually displaying our questions on the canvas that we worked so hard on.

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So that would be the subject of the next lecture where we finally start displaying all of this information

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on the canvas.

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So I'll see you there.