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In this stage, we'll be working towards creating our own class that uses blocks, arrays, hashes, and more. In this video, we'll learn a neat trick about yielding to blocks.
Code Samples
The following code will return the current object in context to a block:
yield self if block_given?
This is useful in cases where you would like to have access to the class inside of a block.
So we're done with our Monster program,
0:00
but I wanted to show you something
really cool that you can do with blocks.
0:02
So, here we have our different actions and
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we're calling them within
the context of a block.
0:13
Let's just see what the last thing
that we have here, okay, monster.hide.
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Let's go to this hide method,
and we yield to the block,
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which means we're coming out of this
method, and calling that block.
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So, it jumps from here,
in this hide method,
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down to monster.hide, right here,
and executes this block of code.
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Something that's kind of neat that we
can do is yield arguments to the block.
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Now we know that from earlier lessons that
we can provide arguments to the block.
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So, we'll just say if
a block is given here,
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let's provide this argument and
what argument would that be?
0:59
Well, if wanted to we could
provide the actions variable and
1:04
then we would have access
to that in the block, but
1:08
let's do something a little more
interesting and yield self.
1:12
Self is the instance of the monster.
1:18
So we'll get the monster
instance inside of the block.
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Which means.
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We could put this in as
an argument called monster.
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And in here, we would have
access to the monster variable.
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And actually, let's just put that in as m.
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And let's print out the actions here,
just to see what it looks like.
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Printed out the scoreboard.
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Let's go back up.
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And this is pretty neat right here,
screams, scares, runs, and hides.
2:01
And let's go ahead and just prove that we
can get access to all the methods in here.
2:07
We define an inspect method.
2:13
We'll just say inspect is the name and
the actions.
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Clear my screen.
2:32
Run this one more time.
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And here we go,
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we've implemented an inspect method
that we call from inside of this block.
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This is not something you totally
need to do, but it is pretty cool and
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something that you will
see in Ruby programs.
2:46
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