What are and how to use lambda functions

A lambda function in C# is a concise syntax for defining an anonymous function that can be defined inline without the need to formally name it.

These functions are useful for writing code in a more compact and readable way. They are especially helpful in situations where you need to define a simple function that you will use only once (such as in filtering, mapping, or reducing collections).

Syntax of lambda functions

The basic syntax of a lambda function in C# is as follows:

(parameters) => expression

Basic Example

Let’s see it with an example. The following lambda function adds two numbers:

var add = (x, y) => x + y;

:::explain
:::explain
Console.WriteLine(add(5, 3)); // Output: 8

Here we have,

• The lambda function takes two parameters x and y
• Returns their sum as the result. :: ::::

Practical Examples

var numbers = new List<int> { 1, 2, 3, 4, 5 };

var evens = numbers.Where(num => num % 2 == 0);

var names = new List<string> { "Luis", "María", "Pedro" };

var messages = names.Select(name => $"Hello, {name}!");

var printMessage = message => Console.WriteLine(message);

printMessage("Hello from a lambda function!");

Button button = new Button();

button.Click += (sender, e) => Console.WriteLine("Button clicked");

:::::::