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00:00:00,400 --> 00:00:03,870
Let's take another look at
the on map method we just wrote.

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00:00:03,870 --> 00:00:07,860
The result of these condition checks
is stored in the inBounds variable.

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00:00:09,960 --> 00:00:12,880
Then the value stored in
the inBounds variable is returned.

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00:00:14,180 --> 00:00:17,230
So if point is found to be inside
the boundaries of the map,

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then the inBounds variable will be true.

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00:00:19,790 --> 00:00:23,110
And the value true will be returned
from this method to the caller.

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Otherwise, if the point was found to
be outside the boundaries of the map,

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this method will return false.

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00:00:30,260 --> 00:00:32,790
I should mention that we can
actually shorten this code a bit and

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00:00:32,790 --> 00:00:36,010
avoid using the inBounds
variable entirely.

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00:00:36,010 --> 00:00:40,190
The way we can do this is to return
the result of this expression right away.

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00:00:40,190 --> 00:00:43,310
Instead of first storing it in
a variable and then returning it.

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We can type return right here instead and
delete the other return statement.

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00:00:53,154 --> 00:00:54,260
See how that works?

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00:00:55,410 --> 00:00:58,270
There's now one less variable in our code.

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00:00:58,270 --> 00:01:01,000
Also stringing a bunch of
operations together like this

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can quickly make the code
difficult to understand.

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00:01:04,020 --> 00:01:08,647
We can alleviate some of this by splitting
the code up into multiple lines like so.

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00:01:11,742 --> 00:01:15,000
I can even indent it to line
up with the line above it.

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This is possible to do
because the semicolon

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marks the end of the statement of code.

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00:01:19,810 --> 00:01:22,856
So I can put this statement on
as many lines as I want and

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C# still knows to treat
it as a single statement.

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Deciding if and when to split statements
into multiple lines really just

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00:01:34,595 --> 00:01:39,080
depends on what you think makes the code
more readable and clearer to the reader.

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I decided to put operations that
deal with the width on one line and

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the height on the other line.

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Indenting so that things line
up vertically can also help.

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All right, we've completed this method.

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Let's go back to the main method in
the game class to try out our new method.

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00:01:57,780 --> 00:01:59,760
Don't forget to save the map.cs file.

32
00:02:01,070 --> 00:02:04,781
We can delete this line and declare a new
point that should be inside our map.

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00:02:08,542 --> 00:02:12,300
Our map is eight units wide and
five units high.

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00:02:12,300 --> 00:02:15,161
So let's create a point
that's in square 4, 2.

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Now let's call our on map method to
determine if this point is on the map and

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assign the value returned to a variable.

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00:02:27,310 --> 00:02:33,322
So I'll say bool isOnMap = map.OnMap and

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then pass it to point.

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00:02:38,673 --> 00:02:43,730
Just for fun, let's call OnMap with
a point that we know isn't on the map.

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Just to make sure that we
get the right answer back.

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I'll overwrite the point variable
we just created with the new point.

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I don't have to declare
the variable again because it's

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already declared as a point up here.

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I just want to assign it a new value.

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The same goes for the isOnMap variable.

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00:03:11,792 --> 00:03:14,743
I intentionally chose to
make a point in square 8,

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00:03:14,743 --> 00:03:18,050
5 in order to illustrate
a common programming mistake.

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At first glance, one might think
that this point is on the map.

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00:03:22,510 --> 00:03:25,890
Because the map has a width of eight and
a height of five.

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However, in programming,
by convention we start counting from zero.

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This means that the point on the bottom
left corner of the map is 0, 0.

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And the rightmost point has an x
value of one less than the width.

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The topmost point has a y value
of one less than the height.

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This is called zero base counting.

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This throws a lot of people off.

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Occasionally even experienced
programmers get bitten

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by what's called an off by one error.

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Let's print out the value of
isOnMap to the Console so

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we can see the result of calling OnMap.

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I'll add the system namespace up here and

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then we'll use Console.WriteLine
to print the value of isOnMap.

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So type Console.WriteLine Is OnMap.

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Copy that and do it again down here.

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All right, when we run this
we should see the word true

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followed by the word false
printed to the Console.

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Let's open the Console and
compile and run this code.

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Looks good.

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When we come back we'll learn more
interesting things about methods.