Lambda Expression in C#

Example 2: Statement Lambda

// Example of a statement lambda

Action<string> greet = name =>

{

    string greeting = $"Hello, {name}!";

    Console.WriteLine(greeting);

};

greet("Rahul");

Output: 

Hello, Rahul!

In this example, we define a statement lambda greet that takes a string parameter name. Inside the lambda, we create a greeting string using string interpolation & then print the greeting to the console. We assign the lambda expression to an Action<string> delegate, which represents an action that takes a string parameter & does not return a value. We invoke the lambda expression by calling greet("Rahul"), which outputs the greeting message.

C# Lambda Expressions and Tuples

Lambda expressions in C# are concise ways to define anonymous methods using the => operator. They are often used with LINQ, delegates, and events. Tuples allow grouping multiple values into a single object. Here’s an example:

using System;

class Program {
    static void Main() {
        // Lambda Expression and Tuple
        Func<int, int, (int sum, int diff)> calculate = (a, b) => (a + b, a - b);
        var result = calculate(5, 3);
        Console.WriteLine($"Sum: {result.sum}, Difference: {result.diff}");
    }
}

Output:

Sum: 8, Difference: 2

Use of Lambda Expression

1. Writing Easy and Simple Delegate Code

Lambda expressions simplify writing delegate code, making it more readable and concise.

Func<int, int> square = x => x * x;
Console.WriteLine(square(5));

Output:

25

2. Passing Parameter in Method

Lambda expressions can be passed as parameters to methods, enabling inline function definitions.

void Execute(Action action) => action();
Execute(() => Console.WriteLine("Hello Lambda!"));

Output:

Hello Lambda!

Frequently Asked Questions

What is the difference between lambda expression and lambda statement in C#?

A lambda expression in C# defines a simple, single-line expression, returning a value. A lambda statement, however, can have multiple lines of code, including statements, but doesn't return a value.

What is the benefit of lambda expression in C#?

Lambda expressions simplify code by allowing concise inline function definitions, making it easier to write, read, and maintain, especially in LINQ queries and delegate usage.

What are the disadvantages of lambda expressions in C#?

Lambda expressions can reduce code readability when overused or in complex scenarios. Debugging and understanding flow can become challenging, particularly for those unfamiliar with functional programming concepts.

Can lambda expressions use variables from outside their scope?

Yes, lambda expressions can capture external variables from their enclosing scope, allowing them to use and modify these variables within their body.

Are lambda expressions in C# the same as anonymous methods?

While similar in purpose, lambda expressions are more concise and can be converted into expression trees or delegates, unlike anonymous methods which are older and typically more verbose.

Conclusion

In this article, we have learned about lambda expressions in C#. We discussed the two types of lambda expressions: expression lambdas & statement lambdas. We also saw the syntax for each type with proper examples to understand how to use them in programs. Lambda expressions provide a concise & readable way to define anonymous functions inline, making your code more expressive & easier to understand. They are particularly useful when working with LINQ queries, event handlers & delegate invocations.

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