Part 25 - C# Tutorial - Method overloading in c#.avi Video Lecture - C

hello welcome to pledging technologies
I'm record this is part 25 in this
session we will learn what method
overloading is and c-sharp let's look at
an example so let's say for example I
already have a function called public
void ad and I want to add two numbers so
we'll have n first number and second
number and all this method does is add
those numbers and print the sum
so consoler tradeline sum is equal to
whatever we want to print and then
basically first number plus second
number add them to the other and print
the sum okay so I have a function with
named ad so let's say I want to have
another function with the same name is
that possible absolutely but the
function has to differ in the number
and/or type of parameters look at this
right now if I go ahead and compile this
then we'll get a compile error because
these two functions have the same name
and they have the same number of
parameters so when I say add let's make
this method static so we can call that
without creating an object so let's make
this static as well so if I call add now
which one of these functions it should
call so we'll have a problem that's why
if you want to overload a function then
probably what I can do is I want to have
another function that can add you know
three numbers so in this case we are
overloading these two functions you know
with a different number of parameters so
it's possible to overload a function
based on the number of parameters so if
I go ahead and say add now you will see
that there are two versions of the Sadd
method one the first version is taking
two numbers whereas the second version
is taking three numbers
so functions can be overloaded on the
number of parameters okay I can overload
another function let's say for example I
want to have I want to add two different
integers maybe end for the number okay
something like this fourth number okay
now if you go ahead and try to call the
side method obviously it will show three
variations of that add method one which
takes two parameters the other one which
takes three and the final one which
takes four okay so basically we can
overlay function based on the number of
parameters okay but on the other hand
let's say I want to add two numbers but
this time I want to add in our two
floats rather than two integers can I do
that with the same method absolutely
float first number float second number
now if you look at this these methods
they have the same name but they have
different types of parameters here it's
an integer data type parameters and in
the second if we have flu datatype
pattern so methods can also be
overloaded based on the type of
parameters look at this there are two
variations one which takes flu datatypes
and the other one which takes integer
data types I can have another method as
well let's say maybe one takes a float
or integer and the other one takes a
float can we do this absolutely
okay so somewhere we are missing
something okay that could be that so
let's compile that bill succeeded now if
I go ahead and call add look at this I
have three add methods okay one which
takes two floats one which takes an
integer and a float and the other one
which takes two in two years okay so a
method can be overloaded based on the
number and type of parameters okay
a method can also be overloaded based on
the kind of parameters okay so what do
you mean by kind you know
in part 17 we have seen different method
parameters output reference value and
parameter arrays
okay these are called the different
kinds of parameters so it is also
possible to overload a method based on
different kinds of parameters for
example here I have a method which takes
let's say three integers into third
number okay now all I want to overload
this method and I want to have another
method which takes three parameters but
this time this one the third parameter
is going to be you know maybe an output
type of parameter okay and first number
plus second number and obviously if it
you can give it a meaningful name
instead of saying third number since we
are using this third parameter to hold
the sum of these two numbers
I will call it sum so this is an output
parameter as I do if you're not sure
about different kinds of parameters I
strongly encourage you to look at video
part 17 in this series so now if you
look at these two add methods they have
exact number of parameters and they are
the same type all of them integers but
the kind of parameters this is a value
parameter I mean and this is an output
parameter okay
so now if I go ahead and say add it will
show me two variations one which takes
all integer value parameters and the
other one which takes two value
parameter and one output parameter so it
is also possible to overload a function
based on the kind of parameter so if we
go back to the presentation so function
overloading and method overloading these
terms they are used entertained
interchangeable they mean they mean one
of the same method overloading allows a
class to have multiple method names with
the same name but with a different
signature that's what we have seen in
the example so far so in C sharp if
functions can basically be overloaded on
the number type and kind of parameters
okay
now the signature of the method okay so
in short we can say you know C sharp
allows method overloading basically in
Sierre loves to have multiple methods
with the same name but with a different
signature so look at the definition
that's when the definition says what do
we mean by the signature of a method
basically the signature of the method in
all forms the name of the method the
type of the parameter number and kind of
parameters so that's what the signature
of the method consists of so if you look
at the slide the signature of the method
consists of the name of the method the
type kind and the number of its formal
parameters but however we have to keep
in mind the signature of the method does
not include the written type and the
params modifier
so the return type of the method does
not form the signature okay it's only
the name type kind and number ok these
form the signature of the method the
return type and params keyword we know
that there are four different kinds of
parameters in c-sharp value reference
output and parameter arrays you know we
know that we can overloaded function
based on the different based on
different kinds of parameters but you
cannot overload a function just based on
the params keyword will let me look at
an example first let's see if we can
overload a function based on just the
written type of your function if you
look at this function the return type of
this function is wired but let me go
ahead and say the return type here
instead of void let's put int as the
return type now and then obviously we
have to add a third number here and just
to make the function complete third
number here and then maybe we'll just
say return first number to a second
number last number because the return
type of this function is integer okay
now if you look at this if I go ahead
and build this now the difference
between these two functions is just that
type and we know that the return type of
a function does not form the method
signature okay
so now if I go ahead and build this I
will get a compiler error already
defines you know the program class
already defines a member called add with
the same parameter types okay so we get
a compile a ssin error so it's not
possible to already function just based
on the return type and it is also not
possible to overload a function just
based on the params keyword let's see
what do we mean by that let's say for
example you know I have a function and
this one takes the params keyword and
since params is a parameter arrays I'm
going to pass this parameter arrays here
and we will not basically do anything
with that parameter okay now let's say
that's an integer array
you know first parameter is integer
datatype integer integer and this one
parameters array and similarly I'm going
to have another function but it's not
going to be params keyword but instead
just a regular integer array now if I go
ahead and build this look at this the
program type program already defines a
member called add the same parameter
types here the parameter type is an
integer array here the parameter type is
an integer array and these two are
integers these two are integers the only
difference between these two methods is
this method has a params keyword but
this doesn't have so it's not possible
to overload methods just based on the
params keyword so that's what the slides
is the signature method basically
consists of the name of the method and
the type kind and the number of its
formal parameters the signature of the
method does not include the written type
and the params modifier so it's not
possible to overload a function just
based on the return type or params
modifier
okay so that's basically function or
method overloading in this slide you can
see in our resources for asp.net and C
sharp interview questions
that's it for today thank you for
listening have a great day