What is an Interface?

The video tutorial explains the concept of interfaces in Java, a core aspect of object-oriented programming. It uses a traffic rules analogy to illustrate how interfaces define method signatures without bodies, which must be implemented by classes. The tutorial further demonstrates the implementation of interfaces in Java using Eclipse, emphasizing the importance of adhering to predefined method signatures to ensure consistency across different implementations.

What is the primary difference between a class and an interface in Java?

• Interfaces only define method signatures without bodies.

• Classes cannot have method signatures.

• Interfaces can have method bodies.

• Classes are used to define constants.

Why are interfaces used in Java, as explained with the traffic rules analogy?

• To allow countries to create their own traffic rules.

• To create a centralized traffic control system.

• To define the hardware used in traffic systems.

• To enforce a set of common rules across different implementations.

In the traffic rules analogy, what is the role of the central traffic team?

• To define a set of base rules that all countries must follow.

• To manage traffic lights in all countries.

• To create unique rules for each country.

• To enforce penalties for traffic violations.

What must a class do when it implements an interface?

• Ignore the methods in the interface.

• Implement all methods declared in the interface.

• Only implement methods that are convenient.

• Define new methods not present in the interface.

What is the significance of method signatures in an interface?

• They define the exact implementation of methods.

• They provide a contract that classes must fulfill.

• They allow for optional method implementation.

• They are used to declare variables.

In the Eclipse demonstration, what keyword is used to define an interface?

• method

• interface

• package

• class

What happens if a class does not implement all methods of an interface?

• The program will run without errors.

• The class will automatically implement the missing methods.

• An error will be thrown indicating unimplemented methods.

• The interface will adjust to the class's methods.

What is the purpose of the 'implements' keyword in Java?

• To inherit properties from another class.

• To define a new interface.

• To indicate that a class will implement an interface.

• To declare a new class.

How does Eclipse help in implementing interfaces?

• It automatically writes the method bodies.

• It highlights unimplemented methods and suggests adding them.

• It converts interfaces into classes.

• It prevents the use of interfaces.

What is the result of commenting out a method implementation in a class that implements an interface?

• The method will be ignored by the compiler.

• An error will occur due to missing method implementation.

• The interface will adjust to the class's methods.

• The program will run without issues.