REST API Automation Testing from Scratch - REST Assured Java - What is an interface?

The video tutorial explains the concept of interfaces in Java, a core aspect of object-oriented programming. It highlights the difference between classes and interfaces, emphasizing that interfaces contain method signatures without bodies. Using a traffic rules analogy, the tutorial illustrates how interfaces enforce a contract for implementing methods. The video also demonstrates how to implement interfaces in Java using Eclipse, ensuring that all methods are correctly implemented in classes.

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

• Interfaces can have method bodies.

• Classes cannot have method signatures.

• Classes are used to define constants.

• Interfaces only define method signatures without bodies.

Why are method signatures used in interfaces?

• To define private methods.

• To provide a default implementation.

• To allow multiple inheritance.

• To enforce a contract for implementing classes.

In the traffic rule analogy, what do the method signatures in the interface represent?

• Country-specific traffic rules.

• Centralized traffic rules applicable to all countries.

• Traffic rules for a specific city.

• Optional traffic guidelines.

What keyword is used in Java to implement an interface in a class?

• uses

• implements

• inherits

• extends

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

• The class will ignore the missing methods.

• The class will not compile.

• The class will throw a runtime error.

• The class will compile successfully.

In Eclipse, what is the first step to create a new interface?

• Select 'New Package'.

• Select 'New Class'.

• Select 'New Interface'.

• Select 'New Project'.

What is not allowed in the body of an interface method?

• Method signature

• Method body

• Return type

• Access modifier

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

• To create a new package.

• To implement an interface in a class.

• To define a new interface.

• To inherit from another class.

What will happen if you try to compile a class that claims to implement an interface but does not provide implementations for all its methods?

• The class will compile with warnings.

• The class will compile without any issues.

• The class will fail to compile.

• The class will run but with errors.

Why is it important to implement all methods of an interface in a class?

• To ensure the class can be instantiated.

• To fulfill the contract defined by the interface.

• To allow the class to inherit from multiple classes.

• To enable the class to use private methods.