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Ruby Arrays
5:03An array is a container of data, similar to a list. In this video, we'll learn what arrays are and how to create them.
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Hi, I'm Jason.
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Let's start talking about arrays in Ruby.
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So far, some basic types that we've
learned about are strings and numbers.
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Strings let us work with textual
data in our programs, and
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numbers with numerical data.
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Let's say that we wanted
to create a shopping list.
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Inside of the shopping list,
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our grocery items could be something
like milk, eggs, and bread.
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We could store that list in
a string separated by commas.
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Or we could use three different strings
called something like item one,
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item two, item three, and so on.
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However, Ruby gives us a type specifically
to work with that kind of data.
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We could use an array.
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An array is a container of data.
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You can think of it as a list.
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We could store all of our different
grocery items inside of the array.
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Arrays can store any type of thing
that we have access to in Ruby.
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Let's see how to make an array
now using WorkSpaces.
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So I have gone in and
created a new Ruby workspace.
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Now, over here in the console,
going to drag this up.
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And we're going to launch IRB
by typing irb and press Enter.
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Now let's go ahead and
create our very first array.
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We'll do that by typing
the name of the variable,
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in this case we'll say we
wanna create a grocery list.
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Now I'm going to type a space and
the equals sign, another space, and
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then capital a, y,
a dot, and the word new.
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This will create a new array, initialized
to the variable called grocery list.
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Now, right below,
you'll see we have an equal sign, and
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a greater than sign,
which is going to be the return value.
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And the return value is an open bracket,
and then a closed bracket.
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That's Ruby's sign for an array.
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Now we can take a look at this grocery
list item and it returns the same thing.
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There’s another way that
we can create an array.
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And that is to use
the brackets themselves.
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So, we can type an open square bracket and
then a closed square bracket and
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we get the same thing.
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Now this is useful, but
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it’s not as useful as having a grocery
list with items inside of it.
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Lets go ahead and create a grocery list
array with our items already in it.
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So we'll put three items in here.
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The way we add items to
an array when creating it,
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is to put the items inside of
the brackets, separated by commas.
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So right here, I've opened the bracket and
we'll put the string milk, and
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then we'll also add eggs and
bread into this array.
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Now we separate the items by a comma.
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So in this case, we have milk as an item,
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and then a comma, eggs,
another comma, and bread.
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We don't put a closing comma
before the closing square bracket.
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Now when we look at the grocery list,
it has the same thing as an empty array,
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except the items are inside.
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Now we're not limited to just strings.
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We could add numbers as well.
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And you'll notice the numbers
don't have quotes around them,
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just like when we were working with
strings and numbers by themselves.
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Now another way to create an array, if we
wanted to create an array of just strings,
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we could use the %w syntax.
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And then we don't have to
surround our strings with quotes.
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Now if we look at our grocery list,
it has the same thing as if we did
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surround it with quotes, and
use the square bracket notation.
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Another thing that we can
do is use an uppercase W.
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Now just like when we were printing
things out with strings and
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having them interpolated, using a capital
W will allow us to do interpolation.
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So I have assigned a variable called
item equal to a string called milk.
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Now, when I create this grocery
list array, using a capital W,
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item will be interpolated.
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And the array comes back with a string
of milk, another string of eggs, and
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another string of bread.
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Try both methods of creating arrays now,
using WorkSpaces.
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