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Now that we know what
gem we want to use and

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have it installed, we have to be
able to use it in our program.

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Let's see how that works
now using work spaces.

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So now that we have the money gem
installed, let's go ahead and

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see how to use it in one of our programs.

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First, I'm actually going to scroll
down the right side of the screen

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on the ruby gem documentation page, and

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I'm going to click the documentation link,
and then we'll see what it gives us.

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Right now, I'm going to click
on the API documentation, and

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then, let's see how to use
it in one of our programs.

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Well, we've done the gem install, so
let's go ahead and see how to use it.

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In this example, there's $10 US.

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Now first, we'll need to require the gem,

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so let's go back to our work space and
create a new file.

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We're going to call this money_example.rb.

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Now once a gem is installed, the first
thing that we need to do is require it.

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So, we’ll require money.

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If only it were that easy in life.

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Now that it’s required we can use it,
so I’m going to go back and

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consult the documentation.

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It looks like we can initialize a new
money instance by calling the class name

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money, and the word new, and then give
it the number of cents in a currency.

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Let's go ahead and try that.

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And, for right now,
let's just print that to the screen.

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Now, I'm gonna click down into
the console, and run this program,

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and it gives us a money instance.

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So, at this point, we've installed a gem,
and used it in a very simple program.

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Let's go ahead and
create another one, more_money.

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And let's print this
to the screen as well.

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Run this one more time, and

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we can see that we have successfully
added two units of money together.

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And that's really all that's required to
use a gem once we've got it installed.

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Just use the require statement.

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Ruby will then find the gem and
import it for you in to your program.

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Generally, the require statement is
going to be the same name as the gem.

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In this example it was called money.

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If we had installed another gem,
such as multi jason,

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we would require multi jason instead.