1
00:00:00,770 --> 00:00:01,960
How did you do?

2
00:00:01,960 --> 00:00:03,679
Let's take look at my solution.

3
00:00:03,679 --> 00:00:07,710
In album class,
I added second method named loan.

4
00:00:10,518 --> 00:00:16,603
Public void Loan And just

5
00:00:16,603 --> 00:00:22,270
like before since this method won't return
a value, I used void for the return type.

6
00:00:22,270 --> 00:00:27,300
Actually, when overloading a method,
the return types have to match.

7
00:00:27,300 --> 00:00:31,670
If they don't match,
the C# compiler will generate an error.

8
00:00:31,670 --> 00:00:34,500
Since this version of the method
will be used to loan out an item

9
00:00:34,500 --> 00:00:40,110
without supplying the loanee's name,
we don't need to define any parameters.

10
00:00:40,110 --> 00:00:43,600
For the method implementation
we could just repeat the code

11
00:00:43,600 --> 00:00:45,350
to set the online field to true.

12
00:00:48,910 --> 00:00:54,300
Or we can call the new loan
method from the old load method.

13
00:00:54,300 --> 00:00:58,675
Notice though that now we're setting
the on loan field to true in two

14
00:00:58,675 --> 00:01:01,660
different places here and here.

15
00:01:01,660 --> 00:01:06,870
Inside of this method overload,
instead of setting on loan field to true,

16
00:01:06,870 --> 00:01:08,900
let's just call the other method.

17
00:01:11,530 --> 00:01:15,107
Doing it this way helps to keep
our code from containing any

18
00:01:15,107 --> 00:01:17,560
unnecessary duplication.

19
00:01:17,560 --> 00:01:21,680
The approach of calling a method
overload from within a method overload

20
00:01:21,680 --> 00:01:23,920
is something that's commonly done.

21
00:01:23,920 --> 00:01:27,240
Next, I updated the GetDisplayText
method to account for

22
00:01:27,240 --> 00:01:29,590
with the Loanee field
doesn't have a value.

23
00:01:34,342 --> 00:01:40,500
So, if Loanee does not equal null and

24
00:01:40,500 --> 00:01:46,666
Loanee does not equal empty string.

25
00:01:50,180 --> 00:01:54,751
Adding the second check to make sure that
the Loanee field isn’t set to an empty

26
00:01:54,751 --> 00:01:57,540
string makes our code more resilient.

27
00:01:57,540 --> 00:02:02,980
This is a very common thing to do to
check to see if a string is not null and

28
00:02:02,980 --> 00:02:03,980
not empty.

29
00:02:03,980 --> 00:02:07,650
This is so common,
that the .net framework string data type

30
00:02:07,650 --> 00:02:10,580
includes a special method that
we can use for this purpose.

31
00:02:14,175 --> 00:02:17,831
String is null or empty.

32
00:02:19,050 --> 00:02:22,090
Then you pass in the string
that you want to check.

33
00:02:22,090 --> 00:02:24,270
In this case, the Loanee field.

34
00:02:24,270 --> 00:02:26,660
Since this method checks
that the string is null or

35
00:02:26,660 --> 00:02:31,170
empty, we need to add the not or
the logical negation operator

36
00:02:31,170 --> 00:02:34,110
before the method call in order
to negate the return value.

37
00:02:36,530 --> 00:02:42,620
So if the method returns false, meaning
that the string isn't null or empty,

38
00:02:42,620 --> 00:02:48,310
the not operator will flip that to true
and satisfy our conditional statement.

39
00:02:48,310 --> 00:02:50,380
So if we have a loanee field value,

40
00:02:50,380 --> 00:02:52,880
then I append the text like
we previously were doing.

41
00:02:54,945 --> 00:03:00,813
And if we don't have a Loanee field value,

42
00:03:00,813 --> 00:03:08,485
we can use this else block to
append the following text.

43
00:03:12,195 --> 00:03:17,110
Currently on loan.

44
00:03:17,110 --> 00:03:18,670
And that's the best we can do.

45
00:03:18,670 --> 00:03:20,425
We simply don't know the Loanee's name.

46
00:03:20,425 --> 00:03:23,338
In the program.csfile main method,

47
00:03:23,338 --> 00:03:29,444
I added a call to the loan method overload
and another call to the return method.

48
00:03:31,431 --> 00:03:34,344
Album2.Loan, this time,

49
00:03:34,344 --> 00:03:39,593
without passing any argument,
and album2 Return.

50
00:03:41,960 --> 00:03:46,070
I also added two additional
console writeline method calls.

51
00:03:46,070 --> 00:03:50,940
Here, let's write album2's information
to the console, and down here.

52
00:03:54,040 --> 00:03:56,830
And lastly, I compiled and ran my program.

53
00:04:04,510 --> 00:04:07,340
And here's the expected output.

54
00:04:07,340 --> 00:04:11,450
Here's when an item is out on loan and
we know the loanee name.

55
00:04:11,450 --> 00:04:15,790
And here's when an item is out on loan and
we don't know the loanee's name.

56
00:04:15,790 --> 00:04:18,260
Excellent job completing
this practice session.

57
00:04:18,260 --> 00:04:20,850
Be sure to check out the next
session in the series

58
00:04:20,850 --> 00:04:25,030
after you've completed the third
stage in the C# objects course.

59
00:04:25,030 --> 00:04:27,510
Thanks for practicing with me and
we'll see you next time.