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Hello, and welcome to Lesson Six in what is our final lesson about Mobile App Development Unit.

So, in this lesson, you're going to complete your app and make it the best it can possibly be in the time that we have.

So, all you'll need for this lesson is your computer and a web browser, you'll also need your project diary, you'll also need your application that you started in the last two lessons, so you'll need access to your code or account.

So, if you're under 13, please ask your parent or carer to log into their account so you can access the work that you've been doing.

So, if you can clear away any distractions that you might have, so, turn off your mobile phone and find a nice quiet place to work.

And when you've done all of that, let's get started.

Okay, so in this lesson, let's mention this, it's all about completing your application.

So, it would be really great if we can include as many as those key programming concepts, that we've learned about so far in this unit.

Include them inside your application.

For example, how can we include some user input inside your application, selection, sequencing and variables? But also I want you to work through those decomposed steps, you've done an awful lot of hard work in the planning.

So, follow through that planning, look at your success criteria in the project brief, look at your decomposed steps and work through them in turn.

And if you do all of those things, you'll get the app to a really good place by the end of this lesson.

Now, hopefully you know by now that I like to start a unit, also a lesson, sorry, with a challenge.

So, this challenge is called debug the code.

So, as you see on the screen, the following code, which is meant to convert currency between British pounds and Australian dollars, unfortunately is not displaying any value in the australian_label.

So, my question to you is, which of the following blocks of code would be most appropriate to help you debug the problem? Okay, so and remember, debugging is trying to find out that error that's happening inside the code.

So, look at those four blocks of code and think, which one would help me do that? Now, before you do that, make sure that you read the main block of code, the top right hand side to get a feeling for what the program's doing, and then work out which of those four blocks of code which would solve the problem the best, okay? So, pause the video and unpause when you think you have an answer.

Okay, so hopefully you've got an answer for that now.

So, let's work through these four blocks of code and see if we can rule out any early on, okay? So, number one says console.

log, australian_label in speech marks.

Now, first of all, there are two problems that would make me rule that one out, okay? Because, if we were to log, if you remember, we've used console.

log before, if you remember when we were doing our tappy top up, we used it when we wanted to show the score incrementing.

So, just to prove to ourselves that it was working, we could see the value of that score variable as it was incrementing, okay? So, that's when we used it before.

So, if we wanted to log the australian_label, because it's in speech marks, it means that wherever we put this block of code, it would only ever show the words australiam_label which is not what we want.

And do we actually want to log what the value of australian_label is? I'm not sure we do it this stage because we already know it's not displaying any value there.

So, we probably, that won't be the first thing that we try.

Now, I've told you about the fact that the speech marks means that would only ever show whatever's in between the speech marks, and that's not what we want.

So, let's rule out number one, and we can also rule out number four too, because that's also in speech marks.

So, which one's going to be better for us, number two or number three? So, what do you think? So, see if you can shout out the answer to the screen for me, you think it's number two or number three? So, three, two, one, it is.

Number two, okay? We are going to use that console.

log, which is a really good one to use.

And we're not going to use a speech marks but we do want to log what's happening with conversion, okay? Because setText australian_label to conversion, what we need to know what's going on with conversion, has it done the calculation? Has it collected any data? Did it collect, did it get the text from the pound variable, okay? So, our first port of call with we're trying to solve this problem will be, working out what's going on with that variable conversion.

If all that's looking, a bit suspective, we can't find the problem, then go on a step further back and see what's happening with the variable pounds.

Is it getting any, and is it getting any value from that text box? You see, we've got getText pounds_text_entry, but we've another thing we can try.

But what we're trying to do here, is we're trying to really determine what the problem is, and see if we can work out how to solve our own problems. So, you can use the console.

log in your app development, to see if you can solve the problem.

So, my other question here is, where would you place this block of code? So, pause the video, we know the console.

log is going to be the one that we want.

So, where do we put it in this block of code? So, pause the video, see if you can answer.

Okay, so, hopefully you got the answer that we would put it just above setText.

We can't put it anywhere else because, if we put it above var conversion, that variable has not been created, and nothing is going to be stored against it.

So, we try and log conversion before it's either that variables even been initialised, then that won't work, okay? So, the only way or place we can put it is work out what's going on with it before it appears in the text label australian_label, okay? So, that would be a great place to put it.

Now, let's go back to your application.

So, hopefully, that debugging task is giving you an indication of you, if you come across any problems with your code in this lesson, try and debug your own problems using console.


But, I'd like to go back and listen to that advice that your former self gave you at the end of lesson five.

So, I'd like to think big and work out what your plan is for this lesson.

So, to do this, you need to open your project on code.

org and get a feeling of where you're up to.

I'd like to open your Project Diary and look at your Milestone 2 slide.

And that will give you an indication of what you did last lesson and what you think you could have achieved or need to achieve, sorry, in this lesson.

Okay, so read over what you achieved, read what you said you're going to achieve, and then unpause this video once you've done that.

Okay, so now you've got a sense of what you thought you could achieve in this lesson when you wrote it last lesson.

So, hopefully, you now feel inspired to really get the job done, okay? Now, don't be too disappointed.

If you don't manage to finish it in this lesson, you can, this application is completely yours, and you can finish it whenever you like.

But I would say roughly, we've got about 30 minutes in this lesson to get you up to the best place it possibly can be, okay? So, remember you should be working through your decomposed steps, you've already done your planning, just continue working through those decomposed steps and treat them as a checklist, okay? So, pause the video.

And most importantly, please have fun with this last opportunity to get your application finished.

So, unpause the video after about half an hour, half an hour's worth of development time.

Okay, so how did you get on with that? Now, hopefully, you've finished your app or gotten to a point where you kind of feel really proud of it, okay? Now, I said, don't worry if you haven't finished it, you can only do so much in the time that you've been given.

But hopefully, at least as a minimum, you've got an app that you've worked out what your graphical user interface elements are going to be, you've put some coding in there, linked to some events, maybe done all the things or if you've done all of those things, then a big well done, you've done an amazing job, okay? So, the only thing left for us to do now, is to evaluate it, let's judge the success of our project, okay? So, what exactly is meant by evaluation? Well, to evaluate something means to judge or to calculate the quality, importance, amount or value of something.

Now, I think there are two really important words there, and they are to judge or calculate.

Now, those are different things.

So, how can we calculate the quality of our project? And how can we judge the quality of our project? Well, I said they're two different things.

Now, if we think about calculation, that's something very factual.

Now, what parts of our project so far can we judge? Can we look at the quality? So, can we calculate the quality based on very factual things? Well, that would be our success criteria.

Now, this success criteria should only allow for yes/no answers.

From that point of view, we can go through our success criteria, give each one a yes or no, and then we can calculate how much of our success criteria we've done.

So, the next part is, how can we judge the quality? Well, this is something that is subjective, and it's based on your opinion.

So, that's the next step that we got to do, we've got to look through our success criteria, and then also add in our opinion, okay? So, what I'd like to do is, I'd like to head over to your Project Diary, again, I'd like to navigate to the success criteria slides, and fill in the table where you can judge it yourself with a yes/no criteria.

Now, that should give you a sense of what you've achieved, and maybe what wasn't achieved, and maybe still could be achieved, and then what I'd like to do, is navigate to the evaluation slide and answer the questions on there.

And that's where you can give your thoughts and your opinion.

So, if you can pause the video now, and then go over to complete your evaluation, and then unpause when you're done.

Okay, for that.

So, that's all for this lesson, and it's all for this unit.

Now, I really hope you enjoyed that, and I really hope you feel massively proud of what you've achieved.

Remember, it doesn't matter if you haven't finished your app.

The app is there, and if you want to complete it, or if you want to develop your own different type of application based on what you've learned, we would really love to see that.

So, if you feel willing to share your app or any future creations with us, please ask your parents or carer to share your work on Instagram, Facebook, or Twitter, tagging @OakNational and using the #LearnwithOak.

So, I'm Ben and that's all from me.

And like I say, I hope you enjoyed it, and I hope to see you on some future units.

Okay, so, bye.