Raja has Published 760 Articles

How can we iterate the elements of List and Map using lambda expression in Java?

raja

raja

Updated on 11-Jul-2020 06:15:14

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The lambda expressions are inline code that implements a functional interface without creating an anonymous class. In Java 8, forEach statement can be used along with lambda expression that reduces the looping through a Map to a single statement and also iterates over the elements of a list. The forEach() method defined ... Read More

Convert an object to another type using map() method with Lambda in Java?

raja

raja

Updated on 11-Jul-2020 06:13:04

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In Java 8, we have the ability to convert an object to another type using a map() method of Stream object with a lambda expression. The map() method is an intermediate operation in a stream object, so we need a terminal method to complete the stream.SyntaxStream map(Function

Type Inference in Lambda expression in Java?

raja

raja

Updated on 11-Jul-2020 06:05:19

846 Views

Type Inference states that the data type of any expression. For instance, a method return type or argument type can be understood automatically by the compiler. Types in the argument list can be omitted since java already know the types of the expected parameters for the single abstract method of functional interface.Syntax(var1, var2 ... Read More

Is it mandatory to mark a functional interface with @FunctionalInterface annotation in Java?

raja

raja

Updated on 10-Jul-2020 14:11:42

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An interface defined with only one abstract method is known as Functional Interface. It's not mandatory to mark the functional interface with @FunctionalInterface annotation, the compiler doesn't throw any error. But it’s good practice to use @FunctionalInterface annotation to avoid the addition of extra methods accidentally. If an interface annotated with ... Read More

How to debug lambda expressions in Java?

raja

raja

Updated on 10-Jul-2020 14:09:46

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The lambda expression composed of two parts, one is an argument and another one is code or expression. These two parts have separated by an arrow operator "->". We can use different IDE's like Netbeans, IntelliJ,  and Eclipse to debug the lambda expressions in Java. It is always possible to create multi-line lambda expressions and use ... Read More

How can we write a multiline lambda expression in Java?

raja

raja

Updated on 10-Jul-2020 14:08:21

9K+ Views

Lambda expression is an anonymous method that has used to provide an implementation of a method defined by a functional interface. In Java 8, it is also possible for the body of a lambda expression to be a complex expression or statement, which means a lambda expression consisting of more than ... Read More

What are the in-built functional interfaces in Java?

raja

raja

Updated on 10-Jul-2020 14:00:23

6K+ Views

The java.util.function package defines several in-built functional interfaces that can be used when creating lambda expressions or method references.Inbuilt functional interfaces:1) Function InterfaceThe Function interface has only one single method apply(). It can accept an object of any data type and returns a result of any datatype.Exampleimport java.util.*; import java.util.function.*; ... Read More

What are the constructor references in Java?

raja

raja

Updated on 10-Jul-2020 13:55:56

219 Views

A constructor reference is just like a method reference except that the name of the method is "new". It can be created by using the "class name" and the keyword "new" with the following syntax.Syntax :: newIn the below example, we are using java.util.function.Function. It is a functional interface whose single abstract method is ... Read More

How to implement the listeners using lambda expressions in Java?

raja

raja

Updated on 10-Jul-2020 13:50:30

1K+ Views

When we are using a lambda expression for java listener, we do not have to explicitly implement the ActionListener interface. Instead, we can use the below syntax.Syntaxbutton.addActionListener(e -> { // some statements });An ActionListener interface defines only one method actionPerformed(). It is a functional interface which means that there's a place to use lambda ... Read More

How can we pass lambda expression in a method in Java?

raja

raja

Updated on 10-Jul-2020 12:50:58

2K+ Views

A lambda expression passed in a method that has an argument of type of functional interface. If we need to pass a lambda expression as an argument, the type of parameter receiving the lambda expression argument must be of a functional interface type.In the below example, the lambda expression can be ... Read More

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