Lambda expression

Lambda expression

Java lambda expressions are a feature introduced in Java 8 that allows you to write concise and functional code. They are a way to create anonymous functions, which are functions that do not have a name and can be passed as arguments to other functions.

The syntax for a Java lambda expression is:

(parameters) -> expression

where "parameters" are the inputs to the function and "expression" is the code to be executed. For example, the following lambda expression takes two integer arguments and returns their sum:

(int a, int b) -> a + b

Lambda expressions can also be used with functional interfaces, which are interfaces that define a single abstract method. For example, the java.util.function.Function interface has a single method called apply(), which takes an argument and returns a result. You can use a lambda expression to define a new implementation of this interface on the fly, like this:

Function<Integer, Integer> square = (x) -> x * x;

This creates a new Function object that squares its input value. Lambda expressions are often used in Java to implement functional programming techniques like map, filter, and reduce, as well as in stream processing and parallel computing.