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How did you do?

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Let's take a look at my solution.

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In the MediaLibrary class, I stubbed
out a method an item named find Item.

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I did that right above
the DisplayItems method.

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Public for the access modifier and
MediaType for the return type.

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Then the name of the method FindItem
followed by a set of parentheses,

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And I defined a parameter of
type string named criteria.

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Then, within the method body,
I start it with defining the variable for

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the MediaType item that will
return from the method.

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MediaType, itemToReturn,

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And we'll set it to null.

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And as a habit, I try to remember to add
the code right now to return the variable.

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That way, I won't forget to do it later.

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Then in between declaring the itemToReturn
variable and returning it,

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I added my for each loop.

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For each, then a set of parentheses and
a set of curly braces.

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Then within the set of
parentheses after the foreach

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keyword, I added (var item in _items).

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Remember that the foreach loop
will loop each item in the array.

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We just need to declare a variable
to use for the item references here,

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and provide the collection that
we want to loop over here.

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Within the loop I added an if statement.

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And for the condition I
called the contains method on

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the item's title property,
passing in the criteria

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parameter, item.Title.Contains criteria.

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The string contains method will
return true if the provided string

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is contained within the string
that you’ve called the method on.

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One downside of this approach is that
the contains method is case sensitive.

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This means that a string that starts with
a capital letter won’t match a string that

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starts with a lower case letter.

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This behavior might not be what
consumers of our class would expect.

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To work around this issue, we can force
both of the strings in our condition to

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lower case letters by
calling the ToLower method.

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So item.ToLower, And

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then on criteria.ToLower.

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Now it doesn't matter that the contains
method is case sensitive because both

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strings will be converted to lower case
letters before the comparison is done.

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Then within the if statement I assigned
the itemToReturn variable to the item loop

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variable And

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I added a break statement to exit the loop
as soon as we found a matching item.

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And that completed my find
item method implementation.

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Then in the program.cs file,

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I started by commenting out all of
the code below the instantiation of

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the MediaLibrary object.

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And then I added a call
to the find item method.

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Var item = mediaLibrary.FindItem and

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for the criteria,

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I passed in arabia with a lowercase a.

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From there, I needed to check to
see if an item was found or not, so

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I stubbed out an if else statement.

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For the condition I checked
if the item wasn't null.

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So, (item != null).

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Checking if the item is null or
not works because I'm returning null

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from the find item method if
a matching item isn't found.

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Within the if statement,

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I added a call to the
mediaLibrary.DisplayItems static method.

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So that's MediaLibrary with a capital M
because we're calling is static method.

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Then .DdisplayItem, and
I'll pass in the item to display.

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And within the else statement I added
a call to the Console.writeLine method,

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passing in the string, item not found

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And lastly, I saved my file,
I compiled and

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I ran my program in order
to test my changes.

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And I've received a compilation error Type
'Treehouse.MediaLibrary.MediaType' does

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not contain a definition for 'Tolower' and
no extension method 'Tolower' of

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type 'Treehouse.MediaLibrary.MediaType'
could be found.

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Let's take a look at that code and
see what I did.

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Here it is.

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I'm trying to call ToLower on item instead
of calling ToLower on the title property.

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That's an easy mistake to make.

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So now it's item.Title property.

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Which is a string,
which we then can call ToLower on.

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I'll save, and
try to compile my program again.

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And now we can see that an item was found
whose title contains the string, Arabia.

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Now let's try changing our search criteria
to something that won't be found in our

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media library.

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How about the word, toy?

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Then let's compile and
run our program again.

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And now we can see that
an item wasn't found.

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Great job.

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Finding an element in an array
is such a common thing to do.

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The .NET framework array type
actually provides a static method for

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doing exactly that, the find method.

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See the teachers notes for
more information.

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When learning the language,
library or framework,

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it's not unusual to overlook
a built-in feature.

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This is a good remainder to
always consult the documentation.

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Getting into the habit of doing that
will save you time by not building or

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implementing features that you don´t need.

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Nice job completing this practice session.

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Thanks for practicing with me and
we´ll see you next time.