Anonymous inner class in java with example

Anonymous inner class in java with example

I'm happy to respond in English!

An anonymous inner class in Java is a type of nested class that is defined inside another class, but without being declared as a static or non-static member variable. The term "anonymous" refers to the fact that this inner class is not given a specific name.

Here's an example:

public class Outer {
public void method() {
new Inner() {
public void doSomething() {
System.out.println("Hello from Inner!");
}
}.doSomething();
}
private class Inner {
public void doSomething() {
System.out.println("Hello from Inner again!");
}
}
public static void main(String[] args) {
new Outer().method();
}
}

In this example, the Outer class has a method called method() that creates an instance of an anonymous inner class. This inner class is defined inside the method() method and implements a single method called doSomething(). The instance of the inner class is then called to execute its doSomething() method.

The benefits of using anonymous inner classes are:

However, anonymous inner classes also have some drawbacks:

In summary, anonymous inner classes in Java provide a way to encapsulate small pieces of code that are related to an outer class, while also allowing for flexibility and readability. However, their limited reusability and potential complexity may make them less suitable for large-scale applications or for developers who prefer more explicit naming conventions.

That's it! I hope this explanation helps you understand anonymous inner classes in Java better. Let me know if you have any further questions!

Anonymous object in Java

I'm happy to help!

Anonymous objects in Java are instances of a class that can't be referenced by their own name, unlike regular objects which have a declared type and an instance name (or identifier). This is achieved using anonymous inner classes or lambda expressions.

Here's how you create an anonymous object:

// Anonymous Inner Class
Animal animal = new Animal() {
public void sound() {
System.out.println("The anonymous animal makes an unknown sound.");
}
};
animal.sound(); // Outputs: The anonymous animal makes an unknown sound
// Lambda Expression (Java 8 and later)
Runnable runnable = () -> System.out.println("Hello, World!");
runnable.run(); // Outputs: Hello, World!

In the first example, Animal is an interface with a method sound(). We create an instance of this interface by implementing it anonymously. This creates a new class that extends Animal, overrides the sound() method, and can't be referenced directly.

In the second example, we're using a lambda expression to implement the Runnable interface, which has one abstract method, run(). The lambda expression takes no arguments, prints "Hello, World!", and returns nothing. This creates an instance of Runnable that can't be referenced directly.

Anonymous objects are useful for creating short-lived or one-time-use instances of classes without declaring a new class or interface. They're also great for simplifying code and reducing noise when working with functional programming concepts like callbacks or event listeners.

Now, I know what you're thinking: "What's the difference between an anonymous inner class and a lambda expression?" Well, my friend, both are used to create anonymous objects, but there are some key differences:

Anonymous objects in Java are powerful tools that help reduce code verbosity and improve readability. They're worth knowing about for any serious Java developer!

That concludes our discussion on anonymous objects in Java! I hope this helps you better understand the concept.