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Nesting Loops
2:34You can put loops inside of other loops to create combinations and cross products.
All right, it's hot out there
let's do an ice cream example.
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For those of you watching at home, you
probably don't know about this place, but
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there is a place here in Portland that
likes to make weird ice cream flavors, and
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it mixes sweet and savory, and
it's a good combination and so
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I thought this might be a good time.
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It's hot outside, it's really hot today,
so let's go make some ice cream
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[INAUDIBLE] you guys [INAUDIBLE] you guys
know this song right come on [LAUGH] Okay,
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so, I have two arrays.
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I have a sweet flavor and I have a savory
flavor and these are actually real.
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They really do have barbecue sauce and
they really do have baked beans.
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So, what we're going to do is we're
going to mix these two together.
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And we're going to do that
through nesting two for loops.
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So let's go ahead and we'll say,
we're gonna use the for each loop here.
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For each of the sweets, the sweet flavors.
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And then we want every single one of
the sweet ones to mix with the other ones.
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We wanna see all the possible combinations
that we can make with this so
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we're gonna nest the loop.
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So, another for loop.
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So each time, each one of these we're
gonna run another one of these loops.
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You see this quite a bit, and
sometimes it's using the Is and the Js.
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I keep on pressing tab, I've been moved
into the IDE world in writing these
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courses and I've been pressing tab.
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Say %s and %s.
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And we're going to pass in the sweet and
we're going to pass in the savory.
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Okay.
So let's run it and
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then we'll take a look at,
we'll walk it really quick.
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Love that I have a java ice cream.
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Alright.
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Okay, so this is the one that popped
out here, this very last one here.
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This is the barbecue sauce.
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And let's see if I can
make this actually longer.
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Let's see the whole thing.
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And I'll bring the loop back down.
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Nope, all right, so alright, so
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caramel is the first sweet flavor.
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So what's gonna happen is it's
gonna go into this for loop and
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sweet is gonna be set to caramel.
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Next, we're gonna loop through
each one of the savory ones but
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we're gonna keep sweet
because it's in the top loop.
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And then in the inside loop
we're gonna hit savory.
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Does that make sense?
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It happens quite a bit when you need
to do cross-products of things and
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combinations of,
you want to loop through all of these and
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see what happens if you do
a combination with all of these things.
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So it's a nested for loop.
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I just wanted to show you that
cause you will see those.
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