Consumer

The consumer interface of the functional interface is the one that accepts only one argument or a gentrified argument. The consumer interface has no return value. It returns nothing. There are also functional variants of the Consumer — DoubleConsumer, IntConsumer, and LongConsumer. These variants accept primitive values as arguments. 

Other than these variants, there is also one more variant of the Consumer interface known as Bi-Consumer. 

Bi-Consumer – Bi-Consumer is the most exciting variant of the Consumer interface. The consumer interface takes only one argument, but on the other side, the Bi-Consumer interface takes two arguments. Both, Consumer and Bi-Consumer have no return value. It also returns nothing just like the Consumer interface. It is used in iterating through the entries of the map. 

Syntax / Prototype of Consumer Functional Interface – 

Consumer<Integer> consumer = (value) -> System.out.println(value);

This implementation of the Java Consumer functional interface prints the value passed as a parameter to the print statement. This implementation uses the Lambda function of Java.

Java has forever remained an Object-Oriented Programming language. By object-oriented programming language, we can declare that everything present in the Java programming language rotates throughout the Objects, except for some of the primitive data types and primitive methods for integrity and simplicity. There are no solely functions present in a programming language called Java. Functions in the Java programming language are part of a class, and if someone wants to use them, they have to use the class or object of the class to call any function.