Lambda Expression in Java SE 8

Lambda expression is a new and important feature of Java which was included in Java SE 8. It provides a clear and concise way to represent one method interface using an expression. The Lambda expression is used to provide the implementation of an interface that has a functional interface. It saves a lot of code.

Java lambda expression consists of three components.

1. Argument-list: It can be empty or non-empty as well.

2. Arrow-token: It is used to link arguments-list and body of expression.

3. Body: It contains expressions and statements for a lambda expression.

To know more about lambda functions in Java 8 visit here13.

Lambda expression is a type of function without a name. It may or may not have results and parameters. It is known as an anonymous function as it does not have type information by itself. It is executed on-demand. It is beneficial in iterating, filtering, and extracting data from a collection.

As lambda expressions are similar to anonymous functions, they can only be applied to the single abstract method of Functional Interface. It will infer the return type, type, and several arguments from the signature of the abstract method of functional interface.

Here’s the resource4 if you would want to prepare for Java 8 interview. Additionally, I would recommend you go through all the official documentation and get yourself prepared. All the very best!!

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Lambda expressions are a new feature introduced in Java SE 8 that allow you to pass functions as arguments to methods or constructors. They are essentially anonymous functions that can be used to define behavior inline without having to define a named class.

Here is the basic syntax of a lambda expression in Java 8:

(parameter list) -> { body }

Here’s an example of a lambda expression that takes two integer parameters and returns their sum:

(int x, int y) -> { return x + y; }

In this example, (int x, int y) is the parameter list, return x + y; is the body, and -> is the lambda operator.

Lambda expressions are often used in conjunction with functional interfaces, which are interfaces that have only one abstract method. For example, the Runnable interface is a functional interface with a single abstract method run(), which takes no arguments and returns no value. Here’s an example of a lambda expression that implements the Runnable interface:

Runnable r = () -> { System.out.println(“Hello, world!”); };

In this example, the lambda expression ( ) -> { System.out.println(“Hello, world!”); } implements the run() method of the Runnable interface.

Lambda expressions can also be simplified further by removing the parameter types and the braces around the body, if the parameter types can be inferred and the body contains a single statement. Here’s an example:

// Explicit parameter types and braces
BinaryOperator add = (Integer x, Integer y) -> { return x + y; };

// Inferred parameter types and simplified body
BinaryOperator add = (x, y) -> x + y;

I hope this helps! Good luck with your interviews!

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