Java 8

Consumer Interface What is consumer interface ? Consumer interface is one of the functional interfaces that Java 8 provides. It is present in java.util.function package.     @FunctionalInterface      public interface consumer<T> Let us look at some of the important points about the consumer interface below. Consumer interface is a functional interface that is it only has on method definition and that method is called the accept . It takes in only one parameter and does not return anything as the output.                 public void accept(T t)                 We also know that functional interfaces can have method of default scope also that is default methods. Well Consumer interface also has one default method know as andThen which takes in a consumer as input parameter.               default Consumer<T> andThen(Cosumer<? super T> after)         This method is used to link the consumers together . That is to make one consumer run after other. Let us look at few exam

Lambda expression  & Functional interfaces basics What is Lambda expression ? To put it in simple terms Lambda expression is a short hand form of functions, more specifically anonymous functions. Anonymous functions are something that is not associated to a class . That is exactly what Lambda expressions are also. How do we write a Lambda expression ? Well there are 3 main sections of an :  (     )                  ->             { }  Input             Arrow          Body parameters Below let us look at individual sections of a  Lambda expression. Input parameters - This section is similar to input parameter section of a method where we provide input parameters. This section usually is surrounded by () brackets. It can have zero or more parameters .  Arrow or Arrow operator - Arrow is something that indicates the flow towards the body of the Lambda expression. IT pretty much just denotes the end of input parameters section and beginning of the body. Body - Body is where we pro