Part 45 C# Tutorial Why Enums Video Lecture - C sharp Enhance your Skills

hello welcome to presume technologies
I'm linkit this is part 45 in this
session we will understand why enums are
required and what are the problems of
not using enums now what is an enum an
enum is a strongly typed constant now
don't worry about what we mean by
strongly typed constant we'll understand
that in a later session in this session
we will basically see a very simple
program you know and we will not use
enums in that program and see what are
the problems of not using enums and then
we will replace those integral numbers
with enums in the next session ok so
let's look at an example first now let's
say I want to create a customer class so
public class customer and this customer
class is going to have two properties
auto implemented properties again if
you're new to properties please watch
the video 0 a session on properties so
public string the customer name and then
this is going to be a non - implemented
property so get and set and similarly
I'm going to have another property and
this one is going to be an integer and
this property is going to be a gender
now so if the gender see if you look at
the gender type it's an integer so if
the gender is 0 then that means the
gender is unknown similarly if the
gender is 1 then it's male if the gender
is 2 then it's female ok
now let's say I want to create a
customer array so customer customers is
equal to new customer array of let's say
I want to hold 3 customers
and obviously since it's an array we
have to use square brackets let's go
ahead and create three customers and
populate this array so customers of 0 is
equal to new customer and name is equal
to let's say mark and since mark is male
we will pass in one okay so basically in
the database you know we are storing
these customers and customer name column
is a ver care column but whereas the
gender column is an integer so obviously
when you prepare these customer objects
and pass them to the database or reading
from the database you know you're moving
these values in the form of integers and
not strings so that's why our customer
object has this property of type integer
okay so we have one customer object
similarly let's go and create two more
customer objects so customer of one and
this is going to be customer of two and
customer of 1 let's say here it's Mary
and since Mary is a female
they'll put two there and finally Sam
and Sam's gender is unknown so we will
say zero okay now if you look at what we
have done so far we have just created a
customer class and we have created a
customer or a free customer objects now
what I want you to do is basically print
out the customer names and genders that
are present in this array and to do that
we can make use of a 4h loop so for each
we can say customer for each customer
and the variable is customer n customers
collection what we want to do we want to
print the customers name and the gender
so how do we do that
console dot write line so name is equal
to and gender is equal to that so name
is equal to the customer object dot name
and similarly we want the customer
gender so we can say the customer object
dot gender but if you look at the gender
property that's an integer so it will
print zeros and ones because these
respective objects you are storing zeros
and ones so the problem with that is
when we display these to the user look
at what's going to happen
mark gender is one many gender is 2 7
January 0 so what's this it doesn't make
sense so what we need to do is probably
have another method and to that method
you pass in the gender you know which is
nothing but you want to do and that
method decides ok if it is 0 then it is
unknown if it's 1 its male and if it's
do it's female so let's write that
method now so let's go ahead and create
that method we will call that you know
maybe get gender method so public static
and the written type of this method is
going to be string because it will
return with its male female an unknown
and then we'll call this get gender and
into this will pass the gender integer
as if it is 0 1 or 2 now we can use
switch here so switch and we will switch
on the past n gender integer so gender
now we know that if that gender is 0 so
case 0 if it is 0 we won't return
unknown similarly if it is
is one then we want to return mail so
case one return mail
similarly case to return female and
maybe default case if the past in value
is not zero one or two then we want to
say return invalid data detected
something like that just to alert to the
users okay the number that's passed in
is not unknown male of females it's
something straight it's wrong data okay
now what we need to do we will call this
method and pass in the gender ID so it
will say get gender and pass that now if
we land this program you will see okay
gender male female okay the output is
fine but then if you look at this
program the problem is here now look at
this we have a set of related integers
you know related numbers 0 1 to 0 means
unknown 1 means male 2 means female you
know how do we know that okay if it is 0
then I want to do some processing for
unknown if it is 1 I have to do some
processing for male you know unless and
until you look at the database or some
documentation you will not know 0 0
corresponds to unknown one corresponds
to male and 2 corresponds to veena ok
and in you know this is a very small
program and this is the only gender you
know we have only gender here and we
have those related numbers 0 1 2 okay
but in reality there may be several
related integral numbers you know for
example I want to store you know then
the directions like north east west
south southeast northeast northwest etc
and obviously to store all this instead
of storing strings we have storing
integer
let's say 0 4 is 2 4 s 3 4 not etc then
to remember all those numbers you know
which number represents to which
direction you know it's really difficult
the program you know becomes more and
more you know up unmaintainable if you
use these integrally in no numbers
actually we have a better way of writing
this program using enums which we'll be
looking at in a later session in the
next session in fact okay so this
program is is less readable and because
of this you know it becomes less
maintainable as the application could
rose and as we keep adding these related
numbers you know it will become
extremely confusing which numbers
respond which values okay so that's
that's what you know if you if I program
you the set of integral numbers then
consider replacing them the thenahms
otherwise that program becomes extremely
you know unreadable and I'm maintainable
as we go along okay actually in the next
session we will see how to replace you
know these integral numbers here here as
well as here now let's say for example
I'm creating another new customer object
and he is male how in this earth will I
know
male means 1 unless and until I go ahead
and look the documentation here or in
the database or in somewhere else okay
that's why it's easy if you replace
these related numbers using enums which
makes your program more readable and
more maintainable which we'll be looking
at in the next session
here you can find resources for asp.net
and C sharp interview questions that's
it for today thank you for listening
have a great day