Lambda expressions in Java 8

24 Oct 2023

In Java 8, lambda expressions were introduced as a new way to write compact and concise code. Lambda expressions allow anonymous functions to be created and passed as parameters to methods or stored in variables. They provide a more functional style of programming and make it easier to work with collections and streams.

What are Lambda Expressions?

A lambda expression is an anonymous function that can be treated as a method argument or assigned to a variable. It consists of three parts:

Parameters: These are the input parameters of the lambda expression, similar to the parameters of a method.
Arrow operator (->): This separates the parameters from the body of the lambda expression.
Body: This is the code that represents the behavior of the lambda expression.

Syntax

The syntax of a lambda expression in Java 8 is as follows:

(parameter1, parameter2) -> {
  // body of the lambda expression
}

Example Usage

Here is an example of how lambda expressions can be used in Java 8:

List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);

// Using lambda expression to filter even numbers
List<Integer> evenNumbers = numbers.stream()
                                   .filter(num -> num % 2 == 0)
                                   .collect(Collectors.toList());

// Using lambda expression to perform square of each number
List<Integer> squaredNumbers = numbers.stream()
                                      .map(num -> num * num)
                                      .collect(Collectors.toList());

In the above example, we have a list of numbers and we use lambda expressions with the stream() and map() methods to filter even numbers and calculate the square of each number, respectively.

Benefits of Lambda Expressions

Lambda expressions offer several benefits, including:

Conciseness: Lambda expressions allow for compact code, making the codebase easier to read and maintain.
Code Reusability: Lambda expressions are reusable and can be used in multiple places within your code.
Parallel Execution: Lambda expressions enable parallel execution of code, which can improve performance when working with large datasets.

Conclusion

Lambda expressions in Java 8 provide a powerful and concise way to write code. They make it easier to work with collections, streams, and functional programming concepts, improving code readability and maintainability. By leveraging lambda expressions, developers can unlock the full potential of Java 8’s functional programming capabilities.