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[MUSIC] 2

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Next stop, we're going to discuss arrays. 3

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And I'm not talking about asking your boss for more money, haha, bad joke there. 4

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We are talking about arrays. 5

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So what is an array? 6

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An array stores into a variable, multiple elements of the same type. 7

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Let's have a look at the example here, an example of how we could craft an array. 8

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We start off with our types, so this is an integer. 9

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You can see we have full, not full, whole numbers down here. 10

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Same thing, full numbers, whole numbers. 11

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If it was a float as our type, then we would have decimal place numbers or 12

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numbers with decimal places. 13

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We could have a string or we could have any other sort of type in here. 14

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We use the square brackets to denote that this is an array. 15

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And then we have a variable name, as we've done before. 16

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This variable is going to store these particular numbers, these particular 17

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values, in this variable, and it will store them at specific locations. 18

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So, at location 0, and all good programming starts counting from 0, and 19

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you can think of it of how many steps is it away from this initial value in here. 20

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So this is 0 steps away and this is 2 steps away at number 5. 21

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So each of these has a position. 22

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If we wish to get access to our number 9 in here, 23

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then we're referring to within our array, odd numbers array, the location number 4. 24

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So back into unity, let us open up our adventure script here, adventuregame.cs. 25

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We're gonna do a little example of an array, so we can see how it works. 26

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First of all, so underneath my text component and 27

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starting state, I will add an integer. 28

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That is a, whoops, wrong brackets, that is a array. 29

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So int, and then our square bracket, oddNumbers. 30

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We're basically typing out what we saw on our screen 31

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just a moment ago, = { 1, 3, 5, 7, 9};. 32

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And then end with semicolon. 33

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So this is the exact thing we saw previously, 34

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int odd numbers one through to nine. 35

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So we have declared our array and also initialized our array. 36

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We could have stopped at this point just here, and 37

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said ignore all this stuff down below and say there we go, 38

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we have declared an array of type integer called oddNumbers. 39

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And then later on, 40

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we will say what the values of this variable is, of this array is. 41

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But for now, we're going to start off by declaring and initializing in one step. 42

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This is all code that we're just playing around with at the moment, 43

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we're not gonna use this in our final game, but I'm using this to 44

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illustrate how arrays work just within our current script in here. 45

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So we have that, now let's go down to our start method, 46

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and just add an extra line at start method. 47

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Let's print out to our console, let's print out number seven from the array. 48

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Let's go through this together. 49

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Debug.Log( ). 50

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Now we don't need our quotation marks cuz we're not printing out a string. 51

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We're printing out our variables so we type in (oddNumbers) and 52

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then within that, we open our square brackets, and we say number 3, 53

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or we add number 3, and then semicolon. 54

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So what this is saying is, print out Debug.Log oddNumbers variable, and 55

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whatever is at position number 3. 56

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Now, we're counting from 0, so 0, 1, 2, 3. 57

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This is will be number 7, if all goes planned, 58

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so Save over into Unity, hit Play. 59

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Look at the console and it should say 7, as it does, fantastic. 60

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Likewise, if we wanted to print out a string, then let's change up, 61

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here's a mini challenge for you again, change this rray 62

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from oddNumbers to days of the week. 63

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And then use Debug.Log to print out, say, Tuesday into the console. 64

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So here's a mini-challenge for you. 65

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Pause the video now and take on that mini-challenge. 66

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Okay welcome back. 67

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Why is it many challenge and not a challenge, 68

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well I guess because I don't have a slide for it therefore it's a mini challenge. 69

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Okay so instead of this being an int, we will change it to a string, so 70

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it's type string we will call it daysof. 71

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Actually I'm gonna show you a trick here, I'll undo that. 72

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In Visual Studio, if we click on the name of something and 73

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we go Ctrl+A A, so double A. 74

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I'm guessing it's Cmd+A, A on the Mac, apologies, 75

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I don't know exactly what that is on the Mac, but on PC. 76

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It is Ctrl AA, 77

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that will allow us to rename all of the things that are called audit numbers. 78

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So, I'm going to type in daysOfTheweek. 79

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And you can see, its naming here, and it's also renaming there. 80

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Because it knows, this is one and the same. 81

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So that's a neat little trick there. 82

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You can click Apply. 83

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And instead of our numbers, we are going to change this. 84

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We need our quotation marks for each of these. 85

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We'll say, mon, whoops, I'll just type it, monday, the abbreviated version, 86

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so we're not here forever. 87

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{"tues", "wed", "thurs", "thurs"}; and 88

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then I'm gonna leave it that the remaining three days of the week. 89

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But I'll save ourselves the extra 30 seconds of typing that. 90

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And then, what were we going for? 91

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Tuesday. 92

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So, this is position 0, and this is position 1. 93

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So, we will change our reference here to 1. 94

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Save, back over into Unity. 95

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Give our script a moment to compile. 96

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Click on Play. 97

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And, then all going to plan, it will say, Tuesday. 98

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Yes, it does. 99

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Excellent. 100

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So, that's the usage of arrays. 101

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Pretty straight forward. 102

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I'm going to remove our example that we've put in here, for now. 103

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We don't need that for what we're doing. 104

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Remove that and remove our Debug down here. 105

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Arrays are super useful if we want to store multiple things in one variable, 106

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and what is the use case for that one? 107

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We're about to do a use case for that. 108

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We're about to implement that in our game. 109

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We're gonna jump here into state, and within state, what we want to do is 110

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have a variable which stores all of our next states. 111

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What do I mean by that? 112

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At the moment we have starting state, let's go ahead and 113

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create two more next states. 114

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I'll right click up to create state, what will we call this? 115

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We'll call this Room One. 116

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Not a very good name for now. 117

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We're going to go through and create our actual story pretty soon, but for 118

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now we're doing, this is a placeholder Room 1 and I'll create a second one. 119

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Right click, Create, State, call this Room 2. 120

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Again, we have stunning state. 121

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We have Room 1 and Room 2. 122

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Room 1, I'll just write a little bit of text in here, I am in Room 1. 123

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And then Room 2, we'll say, okay, this looks like room two. 124

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This is placeholder, so feel free to type whatever you like in there, just so 125

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we've got something. 126

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If we end up, whoops, printing this out on the screen, we know that it's accurately 127

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portraying the right particular state we're going for. 128

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So we now have three states, starting state, Room 1 state and Room 2 state. 129

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These are assets, these are our scriptable object assets. 130

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And we have these three. 131

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So if we wanted to say from starting state, 132

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your options are to go to Room 1 or Room 2. 133

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We wish to store that information in 134

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a variable that has the concept of next state. 135

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and when we look over here and states, 136

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what that will require is that we serialize a variable called next states, 137

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and then we create a new public method where we are returning the next states. 138

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And that is going to be your challenge. 139

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This is a little bit of a deeper challenge, so feel free to stop the video. 140

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Take time to look through what we've worked through previously. 141

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Have a look at how arrays work, and 142

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have a good think about it, I'm gonna give you a few hints. 143

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So if you don't want the hints, feel free to pause the video and 144

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dive in as soon as you're ready. 145

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The summary of what we're trying to do, 146

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is create a public method as we've previously done in here. 147

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This was our previous public method we've already created when called, 148

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returns an array of next states. 149

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So this one when it was called, it returned a string. 150

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So this variable's a string and the return type is a string. 151

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What we're looking to do is to return an array of next states. 152

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So the type is states. 153

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And here are the hints. 154

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if you're ready, if you think that's enough information, 155

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then pause the video and jump in now. 156

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The first hint, is serialized array of type. 157

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So I'm gonna change on the fly. 158

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This should be serialized an array not serialized. 159

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So serialized, 160

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serialize an Array of type State called nextStates. 161

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So that's the first thing. 162

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We're creating our, declaring our variable, nextStates, 163

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and we're serializing that, and it's of type Array. 164

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And the public Public method that returns nextStates is called GetStateStory. 165

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And the return type needs to be the same as the variable type. 166

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Okay, so there are your clues. 167

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Jump in, give that a shot, and 168

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I'll see you back in here in a moment for our solution. 169

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Okie-dokie, our first step here is to serialize a variables. 170

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So serialize field is of type state cuz we're looking for 171

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states, that will be within array. 172

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We denote it as an array without square brackets, and we'll call this nextStates. 173

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Cuz we want to know what are the next states that could comes after, 174

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whatever our current state is, our current state is a starting state. 175

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Now for creating our method, and the bottom of our script here public, 176

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what is this, it's a state and 177

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we need our square brackets because it's an array, it's an array of typeState. 178

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Space. 179

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We will call this GetNextStates. 180

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No parameters. 181

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So open and closed parentheses. 182

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Curly braces and we will type return. 183

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And what are we returning? 184

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Well, we're returning our variable array of type states. 185

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So we're returning nextStates. 186

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And then we'll save that. 187

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So that's creating a State Array called 188

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nextStates, that is being returned when we call GetNextStates from our code. 189

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One last step we are doing in this video, so well done if you've got that challenge 190

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correct well done if you got close to that as well, we'll do one last step in here 191

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and that is jump back into Unity, have a look at an update that we should now see. 192

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If we click on any of these asset files, our scriptable object files here, 193

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we can see that we now have a field called nextState. 194

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It says size zero. 195

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This is our array in here. 196

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And because we've create it as a serialized array, that means we can 197

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dynamically add, just by dragging and dropping we can add into our array, 198

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we don't need to define all the different aspects of our array. 199

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In our code, we can define the aspects of our array straight here in the inspector. 200

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Now, the size we can say is four, for example, and 201

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that will mean we're looking for four elements. 202

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Four elements of our array that will be the next state. 203

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We know we have 2. 204

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So, we can tie in here 2. 205

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That will give us 2, element 0 and element 1. 206

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Room 1 we drag into element 0 and Room 2 we drag into element 1. 207

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Again, we could click on the selector and then we can choose Room 1 and or 208

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2 from there. 209

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Now, another even easier way to do this, I'm just going to change this back to 0. 210

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While clicking on startingState I can come up to the inspector. 211

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There's a little lump, very little lump up in the top right here. 212

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If you click on that, that will lock the inspector so no matter what else I click 213

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on, the inspector will remain locked to the startingState. 214

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That'll allow me to easily click on things without bouncing and 215

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going to a different location. 216

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If I had the lock off and I'm like okay cool. 217

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Now I wanna grab Room 2. 218

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Whoops, now I'm on room two on the inspector, and 219

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I want to stay the inspector on starting state. 220

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So, while that lock is on, I can click on Room 1, hold down Shift, Room 2, 221

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drag both of those over to where it says nextStates. 222

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Let go and it will automatically size it to 2. 223

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And add those two elements into my array. 224

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This is pretty handy, if you have lots and 225

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lots of things that you want to add to an array. 226

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You can just go [SOUND] in one spot, and 227

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you don't have to select them one at a time. 228

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Make sure you unlock the inspector, so 229

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that we don't accidentally stay on on that locked on that asset fall. 230

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Now we can have a look here, and we have our story in our startingState. 231

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We have our nextState that we are going to go to using our array. 232

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And in the next video, we're going to call the method that we've just 233

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created our get next stage method, and we are going to give the player 234

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the option of going to the nextState or the next part of our story. 235

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So great work in this video. 236

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Well done. 237

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Hopefully arrays is making sense. 238

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Again, we will be using these things over and over through out this course, so 239

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if it's only just settling in a little bit into your head, no problem. 240

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This will get crystal clear the longer we go through out this course, and 241

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more we work through the contents. 242

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So great work, I'll see you in the next video.