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Struct
4:15In Ruby, a Struct is a shortcut to creating a class with accessor methods. You could create these yourself using simple classes but structs save you a bit of time.
Now we're going to take a look at structs.
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In Ruby, a struct is a shortcut to
creating a class with accessor methods.
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You could create these yourself
using simple classes, but
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structs save you a bit of time.
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Let's see how structs work
now using workspaces.
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So here is the struct documentation.
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Now if you look at
the notes below the video
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you will be able to see the struct
documentation in there.
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So let's go ahead and
see what a struct is.
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If we scroll down here we can
see that we can create a struct
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by calling new, passing in a string for
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the class that we want, and
then the attributes that are present.
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We can also use the class
name that we want with and
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equals sign and
then Struct.new with the attributes.
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Let's go ahead and see how that works.
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So over here,
I've launched a new Ruby workspace and
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right now, I have a class called customer,
the customer has two attributes.
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A name and an email.
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Now this is something we've seen before.
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This is just a standard class, and
then we instantiate a new customer and
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inspect it, and I'm just gonna
show you how this works, and
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here we see this customer
has been instantiated.
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So, if we wanted to do this as a struct
we could take all this out here.
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And just say customer is a new
struct with a name and email.
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Now I'm gonna clear
the screen down here and
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run this again, and if we look,
we see that we have the exact same thing.
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The only difference is the class has
changed from customer to a struct,
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and it is still a class,
just a struct customer class.
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Now if we wanted to,
we could add in a block here.
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Then anything inside this block would be
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evaluated in the context
of this struct class.
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So we can write instance
methods here as well.
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As an example,
we could say name with email,
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and then evaluate the name,
and the email address.
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And then I'm just gonna print that out
to the screen, customer.name_with_email.
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Now if I were to run this again,
we can see that the name and
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email address are printed out,
just gonna clear that.
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Structs are neat because
each of the attributes
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will be passed as a block
to the each method.
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So I'm gonna clear my screen,
run this again and
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we can see the attribute was printed
to the screen the value of it.
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If we look back at
the struct documentation,
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and scroll down here we can
see there's also each pair.
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That we can pass in so
we get the attribute name and the value.
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So let's go ahead and change that.
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Name and value, and
we'll just say, name and value.
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So I'm gonna save that, run it again, and
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we can see the name and
value are printed out for each attribute.
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Now when you're creating a struct if you
start having a lot of methods in here,
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it might be time to change and
create a real class out of it.
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Structs are mainly meant to be
convenience classes when creating
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something with just a couple of attributes
that you want to access in this format.
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Try creating some struct on
your own now using workspaces.
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