Part 35 - C# Tutorial - Multiple class inheritance using interfaces.avi

hello welcome to prism technologies I'm
brink it this is part 35 multiple class
inheritance using interfaces in c-sharp
we know that we don't have support for
multiple class inheritance however it's
possible using interfaces indirectly
let's look at an example let's say I
have an interface I a interface ia and
in this interface I'm going to have a
method called a method and we have a
class called a which is going to
implement I a interface okay
so public void a method so our class is
implementing that method so let's just
say console that red line a so this just
prints that letter a now I'm going to
have another set of an interface and a
class and this time we will flossed
call that interfaces ib this is the
second interface and the class we are
going to call it as Class B and that's
going to inherit from IB interface and
since this is an IB interface we will
say B method so our class is overriding
that B method so we'll just say B so now
if we look at the code until now it's
pretty simple we have one interface a
class implementing that interface
similarly another interface and another
class implementing that interface now
let's create another class plus a B now
this class is going to have the
capabilities of both a and B and that's
what multiple inheritance tries to
achieve and we're going to do that using
interfaces okay now if we try to do this
class a B is going to inherit from Class
A and Class B and if we try to compile
this code
you know c-sharp will not allow us to do
that it will give us a compiler error
stating that Class A B cannot have
multiple base classes a and B so how can
we do that then from inheritance
concepts we know that you know a class
can inherit from multiple interfaces at
the same time so instead of saying
inherit from Class A and B at the same
time we can say inherit from interface I
a and interface IB okay both of these
interfaces and we know that both of
these interfaces are being implemented
by Class A and Class B respectively okay
now if you have Class A B inherits from
both ia and IB then your class has to
provide implementation for both of the
methods a method and B method okay
so public let's go ahead and do that so
let's say this one is a method and this
is limited okay
but however you don't have to provide
your implementation there since Class A
and Class B have already implemented
them what you can do is you can make use
of those implementations so you can say
a a is equal to UA and similarly B now
what you can do is you can call in the
method a dot a method so you don't have
to provide the implementation again you
just use the implementation provided by
the a class and B class respectively in
a method and B method
so B dot P method that's it so now this
class a B has got the functionality of
Class A which is emitted and
functionality of Class B which is
nothing but B method but now in our
class we are not providing the
implementation we are using the
implementation provided with respect to
a and B classes in those respective a
and B methods all right now how to use
this so if somebody wants to use the
features of good Class A B what they can
do is they can create an instance of
Class A B and now they will be in a
position to call both a and B methods so
a B dot have the a method and similarly
a B dot B method so now if we go ahead
and run this we should get a and B both
the capabilities using this base class I
mean using this class a B so we are able
to achieve multiple class inheritance
not through using the class directly but
using the interfaces so if you look at
this this is exactly the code that we
have seen we have a set of interface in
the class and Lily another set of
interface in the class okay
this class implements that method and
this class implements that method and
what we are doing here is Class A B
instead of making it inherit from Class
A and B at the same time we are making
it inherit from class I mean interface a
and interface B and that's possible in
c-sharp class can inherit from multiple
interfaces at the same time but not
multiple classes and then within that
class we are not reimplemented the a
method and B method instead we are using
the implementation provided by Class A
and Class B by creating instances of
those classes and invoking the a method
and B method on their respective objects
which gives us you know the effect of
multiple class inheritance but using
interfaces and in the main method you
see that you create an instance of Class
A B and invoke the a method and
okay so that's how we achieve multiple
class inheritance using interfaces in
c-sharp on this slide 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