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Branching Statements
5:30You can cause the flow of the loop to change from inside, by breaking and continuing.
Okay, so branching statements.
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We talked very briefly about break,
Ken you talked about
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maybe you're going down the wall and
you go woo, this milk's bad now.
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You want to break,
you want to just get out of this loop.
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Get me out of here, I don't want to drink
sour milk, the rest of these are all bad.
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You can break out of the loop.
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It's a keyword.
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If you're inside of the loop and
you say break, it will stop going.
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Continue, we'll look at here in a second,
but
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what it does is as you're going through
each one of the lines of the code there.
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If you want to not run the rest of
the lines below, you can call continue and
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it will jump back to the top and
run through again.
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Labels are a thing.
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You can be inside of a loop and
say break, and
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somehow they avoided the words saying
go to, but you can go to a label.
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And through the history of programming,
go to is a bad thing.
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It creates what is known
as spaghetti code.
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Which means that you
try to follow code and
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it looks like little strands of spaghetti.
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And it's not a good thing.
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You can solve a lot without using a label.
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So I say use them sparingly,
they're not common.
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And if you get into a situation where
you want to use one, check yourself.
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[LAUGH]
You don't want to
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introduce spaghetti code.
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You don't want somebody looking at your
code, trying to be like, I went up here.
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Am I over here, where?
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You don't want that.
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But they do exist, and you might see them.
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And you can also return.
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If you're inside of a loop, and
there's something that you're, like, oh,
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this method's done.
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I don't need to do this
thing at all anymore.
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This whole method [INAUDIBLE].
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You can just call a return method there,
and the loop will stop and
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jump out, pop out.
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Okay, so the last example that we
have is the t-shirt give away.
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So, while there's prizes left,
we're gonna ask Is the attendee present?
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If they're not here,
we're gonna try again.
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And let's try again here,
can anybody think of what that is?
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What's this try again?
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We're gonna jump back up to the while.
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There we go, continue, excellent.
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So we're going to continue,
we're going to come back up and
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say is the attendant present?
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If they are here,
we're gonna ask what size.
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And the reason why we
don't want to continue,
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we don't want to ask what
size if they're not here.
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There's no point to do this
extra work that's down here,
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we're not gonna give away
a shirt to nobody either.
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So we have to do that.
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So what I did was I wrote some JavaScript
that [INAUDIBLE] the meetup attendees.
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And not 90 people are here, so
we might have a continue problem.
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We might need to check a continue, but
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I am going to randomly sort that list and
give out some t-shirts.
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That sound good?
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All right, you get a shirt,
you get a shirt.
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>> [LAUGH]
>> All right, so
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the t-shirt code is in here,
called prizes.
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Let's bring this down.
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So I have a list that you don't need
to see, that returns a shuffled
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list of all of the Rsvps.shuffled
at the time that we run this code.
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And I am gonna keep track of
the prizes that are given away,
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and I am also gonna keep
track of the drawingNumber.
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And while we've given away five,
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we are going to pull out of
the RSVP list that number.
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This is that for loop.
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We could have written this with a for
loop, but
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notice that I'm using this drawing number.
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We're gonna say, Is the person present?
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If they're here and
I have to remember to type no.
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Then we're gonna continue.
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So we're calling the continue keyword.
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It's gonna go back up to the top.
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It's not gonna run the rest of this.
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And then we're gonna
ask what size you are.
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You can kinda imagine multiple
bits of this continue or
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multiple bits of this break.
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This isn't working and there's a break.
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Let's imagine that we went past 30 people
and nobody's here, we would call break.
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We can put in different
sorts of things in here.
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You could have a continue in here,
you could have a break in here,
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that sort of thing.
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Then we'll do the prizes given away.
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So I'm gonna assume that you
publicly joined a meetup,
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and your name's on the page already.
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Your name might be in Treehouse Video,
maybe.
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So you kind of win two prizes,
you win a shirt and Treehouse and
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you'll be bummed out if you weren't here,
cuz your name's gonna be in a video.
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>> And you don't have a shirt.
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>> If your name's in the video and
you see this at home and you weren't here,
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I'll send you a shirt, okay.
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>> [LAUGH]
>> You're gonna get so busted.
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All right, [LAUGH] all right.
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Her we go.
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Winners, look at winners.
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Is Eric Ewer's present?
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No Eric Ewers.
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So, here we go.
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I'm gonna say no and it's gonna continue.
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Summer present?
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Yeah, all right.
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>> [APPLAUSE]
>> So I'm gonna say anything.
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I'm gonna say, yep, Summer's here,
and what's your t-shirt size?
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>> Small.
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>> Small, okay.
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Path's posse, path post.
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>> Yeah, that's me.
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>> That's you?
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Yeah, all right, so
we'll loop here till we hit five.
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All right.
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I'm not actually gonna
use this data we're just,
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I was kind of trying to
show that we did the.
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Sarah I know her, and
she is not here, Sarah.
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>> [LAUGH]
>> Is Amy present?
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All right.
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>> [APPLAUSE]
>> Ashley.
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>> [APPLAUSE]
>> All right,
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Simone Flore?
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No, Simone.
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>> [LAUGH]
>> Yeah.
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>> [APPLAUSE]
>> There we go.
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