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Using Method Overloading
4:21Let's use method overloading to accept a String as well as a char for our guess.
So we found a fatal error,
when you do not enter a character our code
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that attempts to get the first character
out of input actually blows up.
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That's because there's
not a character there.
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So we could just simply fix that code
there in the prompter class, but
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I've got a hunch that there will be
other code that uses our game class that
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might need to get the first
character of the string as well.
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In an effort to help prevent
possible code duplication and
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keep things dry, let's allow for
a probably common use case.
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We should probably just have our game
accept a string as well as a character.
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Hey, why don't we use that method
signature trick that we learned about
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earlier to allow our apply guess
to accept a string as well.
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So we'll add a new method,
with the same name, applyGuess.
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But it will expect a String for
its parameter, so
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there will actually be
two different methods.
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One that takes a string,
and one that takes a char.
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This way, we are not only making our game
object more usable by other applications,
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but we are also handling common
problems in a single place.
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All right let's squash this bug.
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Okay, so first let's go to game and
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let's make a new apply guess and
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we will say it's a public Boolean
applyGuess same name except for
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the signature String letters
that make sense right.
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Okay, so
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first let's take care of that bug that we
just saw if nothing is entered, right.
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So strings so
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if the letters.length is == to 0.
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Then we better tell them about it,
so we'll,
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throw new IllegalArgumentExceptions.
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We all spell bad.
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No letter found, cool.
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And now we'll pull out our first char.
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So first letter = letters.charAt 0 and
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then we'll call our original method cuz
that takes a char right, and this way
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we're getting all the logic from here and
we don't have to duplicate it here right.
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So method overloading right.
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So here we go.
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So we'll say return, apply, guess.
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First letter but
you know what come to think of it.
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Let's go ahead and let's just pass
in the results of this method call
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without even making a variable.
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Why would we make a variable.
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Here we go, beautiful.
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Now the cool thing is
in our prompter object,
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before we were doing that,
we could just leave guessInput as it is.
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Let's get rid of this line, okay?
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So guessInput is a string.
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We don't need that character anymore and
we'll just switch this to use guessInput.
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There we go.
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And there is no grabbing
the char out of this.
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We're relying on
the GameObject's implementation.
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So much nicer, right?
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That code that we had written there where
we were pulling out the first char would
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probably be duplicated in every single
place our GameObject would ever be used,
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that I can think of, right?
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So even on a web page if it came through,
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you'd have to get the string
that came from the web page and
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you get the first character out of it,
but now we can just pass in this string.
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It's kind of nice.
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We've saved a ton of lines of code for
future devs.
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But first, before we get too cocky,
let's make sure that it still works.
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Clear Javac.
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Cool, so let's make sure it works there,
it does.
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What happens if we guess nothing?
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Here it goes.
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No letter found.
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Please try again.
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Awesome, and it used the same exception
loop that we were using before.
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It works, I'm feeling pretty good.
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Let's move this to done.
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All right, that's all fixed up now.
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And we use method signatures
to keep our naming consistent.
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We now support both strings and chars.
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And no one will have to think about
that zero length string problem again,
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because we've got them covered.
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Whoa, there's only one story left.
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Let's wrap up this exercise and
then finish out our project.
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