JAVA : What is the difference between an Interface and a Class in Java ? SDET Automation Testing

Level up your SDET and QA skills! 🚀 JAVA : What is the difference between an Interface and a Class in Java ?

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In Java, an interface is a collection of abstract methods and constants, while a class is a blueprint for creating objects that defines its state and behavior. Here are some key differences between an interface and a class:

Implementation: A class can be instantiated to create objects that implement the behavior defined by the class. An interface, on the other hand, cannot be instantiated directly but needs to be implemented by a class. A class can implement multiple interfaces, but can only inherit from one class.

Abstract Methods: An interface consists of a set of abstract methods, which define the behavior that must be implemented by any class that implements the interface. A class may also contain abstract methods, but it is not required to do so.

Inheritance: A class can inherit properties and behavior from another class, either by extending a superclass or implementing an interface. An interface, however, can only inherit from other interfaces.

Access Modifiers: In a class, methods and variables can have various access modifiers such as public, private, or protected. In an interface, all methods are implicitly public and all variables are implicitly public, static, and final.

Constructors: A class can have one or more constructors, which are used to initialize objects of the class. An interface cannot have constructors, as it cannot be instantiated directly.

Overall, the main difference between an interface and a class is that a class defines the state and behavior of an object, while an interface defines a contract that must be implemented by any class that implements the interface. Classes are used to create objects, while interfaces are used to define a set of rules that must be followed by implementing classes.

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What is the difference between an Interface and a Class in Java ?

In Java, an interface is a collection of abstract methods and constants, while a class is a blueprint for creating objects that defines its state and behavior. Here are some key differences between an interface and a class:

Implementation: A class can be instantiated to create objects that implement the behavior defined by the class. An interface, on the other hand, cannot be instantiated directly but needs to be implemented by a class. A class can implement multiple interfaces, but can only inherit from one class.

Abstract Methods: An interface consists of a set of abstract methods, which define the behavior that must be implemented by any class that implements the interface. A class may also contain abstract methods, but it is not required to do so.

Inheritance: A class can inherit properties and behavior from another class, either by extending a superclass or implementing an interface. An interface, however, can only inherit from other interfaces.

Access Modifiers: In a class, methods and variables can have various access modifiers such as public, private, or protected. In an interface, all methods are implicitly public and all variables are implicitly public, static, and final.

Constructors: A class can have one or more constructors, which are used to initialize objects of the class. An interface cannot have constructors, as it cannot be instantiated directly.

Overall, the main difference between an interface and a class is that a class defines the state and behavior of an object, while an interface defines a contract that must be implemented by any class that implements the interface. Classes are used to create objects, while interfaces are used to define a set of rules that must be followed by implementing classes.