#65 Need of Interface in Java
Summary
TLDRThe video script explores the concept of needs and design patterns in software development, using the example of a developer requiring a laptop to code. It explains how a developer's dependency on a specific tool, like a laptop, can be abstracted to a more general 'computer' class, promoting loose coupling and flexibility. The script illustrates the transition from concrete classes to abstract classes and interfaces, emphasizing the importance of generalization in coding to handle different types of computers, like laptops or desktops, seamlessly.
Takeaways
- 💻 When joining a company as a developer, you often receive a laptop to work on, such as a MacBook.
- 🖥️ Developers need computers to write code, whether it be a laptop or a desktop.
- 👨💻 A developer class can be created, which requires a laptop object to perform tasks like coding, compiling, and running applications.
- 🧑💼 Companies might provide desktops instead of laptops, which can also perform the same tasks and often faster.
- 🔄 To make the code more flexible, a developer should not be dependent on a specific type of computer (laptop or desktop).
- 🏗️ Creating a parent class 'Computer' can generalize the concept, allowing both laptops and desktops to inherit from it.
- 🔀 Using abstract classes or interfaces helps in creating flexible and loosely coupled applications, where the developer object depends on a 'Computer' type.
- 🔧 Interfaces and abstract classes allow developers to generalize functionality, making it easier to work with different types of objects (e.g., laptops, desktops).
- 🚀 An interface can be used instead of an abstract class to declare methods that any implementing class must define, ensuring flexibility and generalization.
- 🎥 Reviewing the video and practicing the concepts is essential for understanding the power and implementation of interfaces and abstract classes in design.
Q & A
What is the main example used in the script to illustrate the concept of a need in software development?
-The main example used in the script is that of a developer who needs a laptop to write code and build applications in a company.
Why does the script mention the preference for a Macbook for developers?
-The script mentions Macbooks as an example of a desirable tool that developers might prefer, emphasizing the importance of providing suitable equipment for developers to work efficiently.
What is the problem with the initial approach of associating developers directly with laptops in the script?
-The problem is that the initial approach creates a tight coupling where developers are dependent on a specific type of computer (laptops), which limits flexibility and scalability in the software development environment.
What is the solution proposed in the script to make the developer's code writing process more flexible?
-The solution proposed is to create an abstract class called 'Computer' that both 'Laptop' and 'Desktop' classes inherit from, allowing developers to be dependent on a more general concept of a computer rather than specific types.
Why is creating an abstract class for 'Computer' considered an improvement over the initial approach?
-Creating an abstract class for 'Computer' allows for a more generalized and flexible approach, where developers can work with any type of computer, not just laptops, making the code more adaptable to different environments and requirements.
What is the role of the 'code' method in the Laptop and Desktop classes as described in the script?
-The 'code' method in both the Laptop and Desktop classes represents the action of writing and compiling code. It is a method that can be called on any object of these classes to simulate the process of coding.
How does the script use the concept of inheritance to solve the initial problem?
-The script uses inheritance by having both the Laptop and Desktop classes inherit from a common abstract class called 'Computer', which allows for a more flexible and abstract representation of the computing devices used by developers.
What is the alternative to using an abstract class as discussed in the script?
-The alternative to using an abstract class is to use an interface, which provides a way to define a contract for the 'code' method without specifying its implementation, allowing for even greater flexibility.
Why might a company prefer to give a desktop to a developer instead of a laptop?
-A company might prefer to give a desktop to a developer because desktops can be faster and more powerful, providing a better environment for coding and application development.
What is the significance of the term 'loosely coupled' in the context of the script?
-The term 'loosely coupled' refers to the design principle where components of a system are less dependent on each other, allowing for greater flexibility and easier maintenance, as illustrated by the developer being dependent on 'Computer' instead of specific devices like 'Laptop' or 'Desktop'.
How does the script illustrate the importance of generalizing in software design?
-The script illustrates the importance of generalizing by showing how using a more abstract class or interface ('Computer') instead of specific classes ('Laptop', 'Desktop') allows for a more flexible and scalable design that can adapt to various types of computing devices.
Outlines
💼 Understanding Developer Needs and the Role of a Laptop
This paragraph introduces the concept of a 'need' in the context of software development. It uses the example of a developer joining a company and the expectation of being provided with a laptop to write code and build applications. The scenario explores the dependency of developers on laptops for their work and illustrates this with a hypothetical class structure in programming, where a 'Developer' class might interact with a 'Laptop' class to perform coding tasks. The paragraph emphasizes the practicality of having a laptop for developers but also raises the question of flexibility and dependency in tool usage.
🖥️ Transitioning from Tight Coupling to Loose Coupling with Abstraction
The second paragraph delves into the principles of object-oriented programming, specifically focusing on the concepts of abstraction, interfaces, and inheritance. It discusses the issue of tight coupling between the 'Developer' class and the 'Laptop' class, suggesting that this coupling limits flexibility. To address this, the paragraph proposes the creation of an abstract 'Computer' class, from which both 'Laptop' and 'Desktop' classes can inherit. This abstraction allows a 'Developer' to work with any type of computer, thus promoting loose coupling and making the code more adaptable to different environments. The summary also touches on the use of abstract classes and interfaces to generalize the concept of a 'Computer', emphasizing the importance of these programming constructs in creating flexible and maintainable code.
Mindmap
Keywords
💡Need
💡Interface
💡Developer
💡Laptop
💡Desktop
💡Abstract Class
💡Coupling
💡Method
💡Inheritance
💡Interface (in programming)
💡Generalization
Highlights
Understanding the concept of 'need' in software interfaces through the example of a developer's requirements.
Developers joining a company expect to be provided with a laptop to write code and build applications.
The example of a 'laptop' class in object-oriented programming to illustrate the dependency of a developer on a tool to perform their task.
Introduction of a 'code' method within the 'laptop' class to simulate the process of writing, compiling, and running code.
The scenario where a developer requests a laptop to write code, emphasizing the need for a specific tool.
The creation of a 'laptop' object to fulfill the developer's need for a tool to write code.
The concept that every developer might need a different laptop, implying the need for multiple objects.
The alternative of a 'desktop' being provided by a company instead of a laptop, challenging the developer's dependency on a specific tool.
The introduction of a 'computer' class as an abstract concept to generalize the type of tool a developer might use.
The idea of 'loose coupling' in software design to make applications more flexible and not dependent on specific implementations.
The demonstration of using a 'computer' reference to pass either a 'laptop' or 'desktop' object to a developer.
The explanation of how the 'code' method is called based on the actual object passed, not the reference type.
The practical application of abstract classes and interfaces in software design to improve flexibility.
The transition from concrete classes like 'laptop' and 'desktop' to the abstract 'computer' class for better design.
The importance of abstract classes in creating an abstraction layer that simplifies the complexity of software design.
The option to use interfaces instead of abstract classes for even greater flexibility in software design.
The demonstration of how interfaces allow for an 'interface reference' rather than a class reference, enhancing design flexibility.
The encouragement for developers to generalize concepts in software design, similar to how we generalize in real life.
Transcripts
let's try to understand what is a need
for the interface now for that let's
take an example here so let's say we
have a class here and so the example
which I'm trying to take here is for the
developers let's say when you join a
company of course as a developer when
you join a company you want to write
code right you want to build application
and if you have seen the trend whenever
you join a company most of the company
will give you a laptop to work on and
luckily if you get a Macbook that's
great so they give you a laptop right so
that's that's the thing right if you
want to work in a company let's say if
you go to our office and if you want to
work there you will say hey I want a
laptop so in this case let's say you are
a developer okay so I will say you are a
deaf right of course you're a human but
let's say you're a developer and then as
a developer what you do you make
applications right or maybe I can say
you write code
ulcerative app you you develop
applications right now when you say you
are developing an application of course
you will say
coding okay you're building an
application here of course as a company
if I want to build a product I have to
hire developers now in this case let's
say if I hire a developer let's say
developer name is Naveen and then if you
say new developer and with this object
Naveen I can say Naveen dot Dev app
right so I want I mean to develop
application and if I compile this code
and if I run it perfectly works right
now let's say
if I say hey you know I will make an
application but I need a laptop first I
cannot work without laptop but we don't
have laptop right so what I will do is I
will create a laptop class I will say
class laptop and in this class laptop of
course in a laptop what you do is you
write code and I can say calling
right in fact what laptop when you say
code you it basically you code the new
compile then you run so you do all those
stuff right so I'm saying code compile
and run and now as a developer what I
want is if I if you ask me to write a
code what I will do is I will just say
hey give me a laptop so basically you
have to accept a laptop object here
that's right you can also pass the
object so this developer will say give
me a laptop and then I will write code
so here instead of saying this you can
simply say lab dot code right now since
you have a laptop object you can
basically call this method called code
and it will work so what I'm doing is I
got two classes here which one is
developer and second is laptop and
inside laptop class I have a method
which is code and then once I pass this
object I can simply code right now the
only thing is when you ask a developer
to write a code developer will say hey
give me a laptop so that means first you
have to create an object of laptop so I
was a laptop lap is equal to the new
laptop so we got a laptop object of
course every developer needs a different
different laptop object so let's say if
you hire five developers you need five
laptops to give them
okay I was a lab here now this should
work there's no problem if you can see
the code everything should look good uh
if I run you can see it still works so
basically we are saying code compiled
one so what you're doing is from the
main method you are calling Dev app
which is here and then you are passing
the laptop object okay so you're passing
this object here and when you accept
this object you're calling the code
method so it will call this code method
and you execute this part everything
works well right now the only thing is
do you really need a laptop see in some
companies they give you a desktop right
so if you go to the office you they will
have a desktop where you have a monitor
you have a desktop a good desktop which
works so why as a developer you are
asking for a laptop what if company
wants to give you a desktop you can't
say hey I cannot work without laptop
right you should be able to work on any
computer
so let's say you also get an option of
desktop there in fact in desktop as well
I can do the same thing but I will say
faster like desktops are always faster
than a laptop right so you can see when
you're coding uh it says code compiled
One faster because it works fast now
what if a company says hey you know I we
don't have laptops with us but what we
have is we have desktop our desk is
equal to new desktop and they don't want
to pass the laptop object so that when
the company says Hey Naveen you have to
work you have to make an application and
what we are giving you is not laptop we
are giving you a desktop now nobody will
say I can't work you can see Naveen says
I can't develop application because my
application only needs laptop you can't
do that so writing laptop here is an
issue we can't do that right so how do
we solve this problem and that's what
you know when I was talking about
abstract class and interface I told you
about the design thing right so when you
back an application you have to make it
more flexible here we are what you are
doing is you're doing a tight coupling
here which is you are saying that
developer is dependent on a laptop no
developer is not dependent on laptop
developer is dependent on a computer a
computer can be anything your computer
can be a laptop a computer can be a
desktop so if you want to improve this
example what you can do is you can
create a class called computer okay and
in this computer class you can say
public void code and basically you know
I want to keep this empty because I
don't want with a code because we don't
computer does not exist right it's just
a concept
and I can say a laptop is actually a
computer so when you do that the
advantages in fact desktop is also a
computer so when you do that what
happens is now both this laptop and
desktop they are computer so when I'm
creating a reference of it so can I say
computer lab is equal to new laptop and
computer
desk is on the new desktop we can do
that right we can create a reference of
a patent class an object of a subclass
and that's what we are doing here same
thing can be applicable here right as a
developer you are focused more on the
computer not on laptop or desktop the
moment you do that you can say
everything is working there's no problem
here is because what you are passing
here is Dex desk right which desktop
basically but that is referred as a
computer and what you are referring here
is a computer there's no mismatch here
you're passing a computer reference you
are accepting a computer reference but
when you call code it will be called
based on what object you are passing so
basically we are passing desktop object
So when you say code it will call the
code of the desktop not of the laptop
let me show you so if I compile this
code and run you can see it says faster
that's desktop but now if I pass a
laptop let's say computer company
decided to send you a laptop and now
when you compile and run you can see it
says code compile and when there is no
faster here that means that's laptop
code
so that's how you design the application
right to make it Loosely coupled where
your developer object is not dependent
on the laptop or desktop it is dependent
on the computer any computer will do a
mobile phone also do because that's a
computer now there's one change
see if it if you look at this code we're
doing nothing right so instead of
defining it here can I simply declare
this and we know when you're declaring
it we can make it abstract and since
your method is abstract you can also
make your class abstract and problem
solved and that's the importance of
abstract class right you can create that
abstraction layer where you say we are
not working with laptop and desktop in
real world as well we do that right uh
sometimes we don't mention rows or
lilies or sunflower we simply say
flowers right we don't say apartment or
a villa or anything we say house right
so we try to generalize things in real
life in real in virtual world as well
it's good to generalize things instead
of specializing things there's one more
don't you think we can also use
interface issue of using abstract class
so we are using interface we don't need
public abstract the only change you have
to make is instead of using App extends
we have to say implements
and that's the beauty of interfaces
right
uh I know we have written a lot of code
maybe you have to watch this video once
again to understand and try it by
yourself that's when you will understand
the power of the interfaces and what you
are creating here is not the classes
reference we are getting interface
reference yeah and that's the importance
of the interface
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