Original subtitles

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Hey,

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you've reached the final project and as you've seen at the beginning of today's

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lessons, I showed you what we're going to be making,

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which is a sort of choose your own adventure game.

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I don't know if you've ever read those

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choose your own adventure books where you flip to a different page if you

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make a particular choice and then the story kind of evolves as you make your

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choices.

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Now we're going to make a very simple version of that using what we've learned

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about conditionals: if, else, elif statements as well as everything we've done

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previously. So you've already seen what the final outcome should look like.

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And if you want to review it again,

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just head over to treasure-island-end.app brewery.repl.run.

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And here you'll see essentially the game in action.

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So it start off asking you, you're at a crossroad. Do you want to go left or right?

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And then you have to type your choice. If you selected left,

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then it's going to take you to a Lake and it asks you whether if you want to

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wait for a boat or swim across. So let's go ahead and wait for a boat.

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And then the final step is it asks you which door would you like to go through?

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Red, yellow, or blue. Now depending on your choice,

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you'll either end up with game over or you'll end up with, um,

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winning the game.

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So the basic setup for this game looks something like this.

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And I've included a link to this flow chart in the starting repl.

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So repl.it/@appbrewery/treasure-island-start

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and of course you'll find all the links in the course resources as always.

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But if you scroll down,

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there's a link right here that takes you to this flow chart.

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Now the first question you're going to ask the user is to make a choice between

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left and right. Now you can use my wording. Um, if you want your at a crossroad,

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where do you want to go? Type left or type right?

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But I think the fun part of this challenge is really creating your own story,

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right?

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But somehow get them to choose between left and right. If they choose right or

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any other condition for that matter,

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tell them that they've lost game over for some sort of reason.

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In my case, if they had chosen, right,

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the reason is because they fell into a hole. Game over.

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But I think you're far more imaginative than I am.

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So go ahead and use all of those skills and make your game really fun.

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Now if they've chosen left on the other hand,

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then we're going to take them to another question that asks them whether if they

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want to swim or whether if they want to wait for a boat. Um,

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and if they swam, then it's going to be some form of game over.

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There's crocodiles, there's, um, whatever it may be, but they can't continue.

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But if they chose wait, then we take them to the third and final question,

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which asks them to choose between three doors.

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And if they choose any door other than the yellow door, then they would lose.

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But if they chose the yellow door, then they somehow win.

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Now notice how each of these just says, game over, game over, left or right,

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but you know,

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the idea is really to use your creativity and make this game really your own.

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Now one thing to remember though is that when the user types in a answer,

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let's say left or right, they might type it like this, um,

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with an upper case R or they might type it like this, all lower case.

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Have a think about how you might make sure that no matter which version they

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typed, you're still going to be able to catch their command essentially.

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So have a think about what you've learned in the previous lessons and take a

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look at this flow chart,

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then head over to the starting project and you can get started writing your

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code. Now if you head over here and what you see is sort of like a mumbo jumbo

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a bunch of characters,

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then the reason is probably because there's not enough space for this ASCII art

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of a treasure chest to display. So you can either do as I did,

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reduce the size of the console or alternatively and probably easier is to change

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the layout to stacked, make it go with the bottom, collapse

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this left hand pane

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and then you've got as much space as you have to work with.

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Now ASCII art is really cool because it basically just uses a bunch of characters

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that you know and love,

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like the comma and the equal sign and all of these things that, um,

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together make up a picture. And you can find your own ASCII art if you just go to

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ascii.co.

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uk/art and you'll see a whole bunch of different topics.

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Um, and they've grouped a lot of things together into individual pages.

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So if you wanted to a rhino ASCII art,

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then you can find a whole bunch of rhinos that people have drawn.

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But the easiest way is, of course, using a command F if you're on a Mac or control

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F if you're on a Windows machine and then just search for the thing that you

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want. So, for example, I went and searched for treasure,

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and down here I found this brilliant treasure box, ASCII art,

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which is what I'm using to print inside this print statement.

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Now notice how there's three single quotes that are at the start and there's

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three single quotes at the end.

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Basically what the single quotes allow you to do is to create multiple lines of,

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um, a string essentially.

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So notice how if I go ahead and delete all of these, uh,

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single quotes and I only had a set of double quotes,

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then it actually doesn't quite work.

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It gets quite confused, um,

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because it thinks that this is where the line ends. But in fact,

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I want it to print all of this out. So to do that,

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instead of using a double quote, I use three single quotes.

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And at the very bottom I tell it, well,

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this is the end of my multi block string by using three single quotes as well.

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So I have a go at running that and you should be able to see that in your

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console

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you get this little treasure Island ASCII art being printed along with the two

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sentences that begin the game. So have a look at the flowcharts, um,

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have a play around with the ASCII arts and also have a look at the final

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version of the app so that you can go ahead and create your own version to

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complete this challenge. Pause the video now and give that a go.

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Yeah.

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All right,

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so let's see if we can replicate the functionality or the logic that's shown in

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this diagram into a treasure Island game.

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So the first thing it has to do is we have to ask the user whether if they want

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to turn left or right, and after we ask the user this question,

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we're going to want to capture their input, right?

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So let's go ahead and create an input function and ask our question.

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Yeah.

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Now notice how when I use my double quotes around my string,

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the double quotes that are inside the double quotes are interpreted as code

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because it actually thinks that this is the end of the first string,

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this is the second string, and this is the final string.

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This is how the computer is going to see it. Now,

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previously you saw that we could do the trick where we change this to single

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quotes instead, but if like me,

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you have this case where you have the your with the apostrophe,

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then it's going to think that this is actually the end of the first string,

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this is the second string and this is the third string.

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So this doesn't actually really help us.

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Now what we can do when we want to tell our computer that what I'm writing is

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actually not code, just see it as text.

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You can get it to ignore a symbol afterwards by using the backslash.

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So this way it basically escapes the string and it will see it as text and now

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we have a complete string like this,

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and this is just going to be interpreted as text because we told it to with the

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backslash. Now of course,

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there's other ways that you could have gone around this.

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You could have just simply said you are at at a crossroad rather than using the

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apostrophe. But more often than not,

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you'll need to use a symbol that you'll need to escape and you can do that with

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the backslash. So that's just a quick tip. Now at this point,

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the user is going to type a message left or right.

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So let's go ahead and save that to a variable.

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Let's call it choice1 equals their input.

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Now, remember how I said they could be typing the answer as Right or as right.

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So how can we make sure that when we're doing our checks using if statement,

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we ignore the casing?

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Well one way of doing this is we can use the lower function to change their input

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no matter how they wrote it, Right, right or RIGHT,

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it should all be converted into lowercase, to this version.

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That way we have one thing that we can consistently check for in our if

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statement, which is coming up next.

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So we can say if choice1 is equal to, remember the double equals is checking

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whether a left hand side and righthand side is equal

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and a single equal sign is assigning the right-hand side to this particular

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variable name. Now if choice1 equals the string, right,

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then it's pretty much game over for our player.

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So let's go ahead and add our colon and print something like Game over.

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Of course, we can elaborate this a little bit more as to why it was a game over.

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Well, because you fell into a hole.

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This is like the ITTI game from the 1980s. Lots of holes.

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Um, so you fell in to a whole, game over. Um,

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but what if they had chosen left instead?

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Well that takes them on to the next question.

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So that's the option that will allow them to continue along the game.

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Now, in this case, we could use an else statement and say, well,

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if they didn't choose right then they probably chose left right?

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But they could've also chosen like a option that was completely not listed.

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They could have just written something like this and it would still trigger the

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else statement.

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So what we should actually do is to switch it around.

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So namely we should say if choice1 is equal to left,

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well in that case, then they continue

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in the game. But otherwise, namely,

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if they chose right or anything else for that matter,

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then it's pretty much game over.

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So this format makes a lot more sense if you want to continue along the left

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side of the branch, this way.

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Now another thing that you might've realized because we learned about combining

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different conditions is instead of using the dot lower to change the input to

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lowercase,

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you could have also said if choice is equal to left or if choice1 is

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equal to Left, spelt like this, that will both work.

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Um,

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but I think in terms of succinctness and less code writing,

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I think this makes a lot more sense to me.

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So I'm going to continue with this version. But if you did it the other way,

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that's perfectly valid as well.

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Now if their choice1 was left, then they get taken to the next question.

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Do you want to swim or do you want to wait?

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So let's go ahead and continue the game and create another input. In this input

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we're going to ask them a question and say,

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you've come to a Lake,

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there is an Island in the middle of the Lake. Type "wait" to wait for a boat. Type

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"swim" to swim across. Cool.

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So we've actually got the same problem as we had before,

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namely that this is being interpreted as code rather than as a continuous single

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string. So do you remember how we fixed this previously?

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And if you got stuck on this,

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I recommend having a go at this yourself before I show you the answer.

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Alright,

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so previously we said we were going to switch it to single quotes instead so

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that these double quotes become interpreted as just normal strings.

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But of course, we've got this you've, we could, of course, change it

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to you have instead of you've, but if we want to escape the string,

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we just add a backslash and now everything is colored in this sort of pinkish

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color to indicate it's all interpreted as a string,

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which is exactly what we did previously. Now in terms of this input,

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they're going to type wait or they're going to type swim.

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So let's go ahead and lower the casing for it as well.

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And then we're going to save it inside a choice,

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we're going to say choice2. Now be really careful and mindful of your

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indentation because if you wrote it like this,

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then it's going to be creating some errors for you because this choice2 input

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line has to run when this choice1 is equal to left.

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Otherwise we're going to get an indentation error.

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So let's go ahead and indent it here to show that this part is inside this if

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statement and will only be executed if this is true.

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And then we get to check our choice2.

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So if choice2 is equal to wait,

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then it means that the game will continue.

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But else,

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so if they typed swim or anything else for that matter,

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then the game is going to end.

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So we're going to print and tell them that something terrible happened.

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"You got attacked by an angry trout.

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Game over." Now we can continue along this path,

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so we're down to here now.

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And the final question we're going to ask the user is which door do they want to

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choose?

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So here I'm going to use an input to send them the message that "You arrive at

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the Island unharmed. There is a house with three doors, one red, one yellow,

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one blue. Which color do you choose?"

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Now I'm going to save their choice inside a variable called choices, lower

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case the answer that they provided,

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and finally I'm going to use if, elif and else to check which one they chose.

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So if choice3 is equal to red,

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elif choice3 is equal to yellow,

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elif choice3 is equal to blue.

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And then I've got a else.

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So here are four possible things that could happen. If they chose red,

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then I'm going to tell them that it's game over,

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but it's going to be some sort of creative version of game over.

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So maybe something like, uhm,

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it's a room full of fire. Game over. If they chose yellow on the other hand,

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well that's going to be the room where the treasure exists.

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So I'm going to print. Um, you found the treasure, you win.

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If they chose blue, they also end up with game over.

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And I have to give them a different reason. Now,

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if you had decided that if they chose anything but yellow,

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the way that they're going to game over is the same. Say if, you know,

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if you chose red, it's a room full of fire, game over. If you chose blue,

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it's a room full of fire game over. Anything else

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is also going to be a fire, game over.

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Well then you could just use if and else.

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But if you wanted each choice or each door to have a different outcome for the

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user, say the red door has fire,

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the blue door has beasts and if they chose the wrong door then they're going to

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get something like you chose a door that doesn't exist, game over.

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So can you see that depending on whether

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if you want to give the user a different um, print statement,

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um, based on their choice, then you would use if, elif, else.

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But if you actually just wanted to give them the same feedback,

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which is game over, then you could just use if and else.

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Now let's run our game and just make sure that it works.

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So I'm going to go left because I know it continues and then I'm going to wait

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for the boat and that allows me to get to the final condition.

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And if I choose yellow, I know that I'll win.

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Now if you want to change the formatting because having the input at the end of

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the sentence doesn't look as good as letting the user type it on a new line,

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like what we've got here, then you can simply, if you remember,

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just add the new line,

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which is a \n at the end of your inputs.

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Like so. So how did you get on with this challenge?

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And if you didn't manage to do it right or if you've done it right,

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go back and try and modify it.

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See if you can add some more conditions or see if you can make the game over

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messages a little bit more interesting than what I've written.

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See if you can modify and make it really your own. Have fun with that

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and in the next lesson, I've got more exciting things coming up for you.

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So hopefully you've scheduled some time for tomorrow to complete the next day's

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lessons. But for now, it's goodnight from me.