Functional Interface in Java

Ref : https://waytoeasylearn.com/learn/functional-interfaces/

A functional interface is an interface that contains only one abstract method.

These interfaces are used primarily with lambda expressions and method references.

Example of a functional interface:

@FunctionalInterface
interface MyFunctional {
	void doSomething();
}

Built-in Functional Interfaces

Java provides many built-in functional interfaces such as:

1. Predicate

2. Function

3. Consumer

4. Supplier

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1. Predicate

   Predicate<T>: Represents a Boolean-valued function of one argument.

   
   

2. Function

   Function<T, R>: Represents a function that takes an argument of type T and returns a result of type R.

   
   

3. Consumer

   Consumer<T>: Represents an operation that takes a single input argument and returns no result.

   
   

4. Supplier

   Supplier<T>: Represents a function that supplies a result of type T without taking any arguments.

   
   

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Key Points of Functional Interface

• One abstract method

• Can have multiple default or static methods

• Can be used with lambda expressions

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