4 uses of lambda expression in C#

4 uses of lambda expression in C#

In this tutorial we will see 4 different ways to use lambda expression in C#. If you have used Entity framework or LINQ , you probably aware of lambda expression. Here, we will see few situations where we can use lambda expression.

Search from Collection

If we want to search some element from List (or generic list) we can use lambda expression. Have a look on below code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace DesignPattern
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> Lst = new List<int>();
            Lst.Add(100);
            Lst.Add(200);
            Lst.Add(300);
 
            int Value = Lst.Find(m => m.Equals(100));
            Console.WriteLine(Value);
            Console.ReadLine();    
        }
    }
}

Find series of number

Here is another example of lambda expression, In below example we have used it to find all even number from collection.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace DesignPattern
{
    class Program
    {
        //Find Even Number
        static void Main(string[] args)
        {
            List<int> numbers = new List<int> { 1, 2, 3, 4, 5, 6, 7 };
            var evens = numbers.FindAll(n => n % 2 == 0);
            foreach (int a in evens)
            {
              Console.WriteLine(a);
            }
            Console.ReadLine();    
        }
    }
}

Use in place of function

No need to write function when task is very little. We can use lambda expression associate with delegate.  In below example we have set one delegate which will perform square operation.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace DesignPattern
{
    class Program
    {
        delegate int del(int Value);
        static void Main(string[] args)
        {
            del MyDelegate = X => X * X;
            Console.WriteLine("Result is := " + MyDelegate(5));
            Console.ReadLine();    
        }
    }
}

Use with Func keyword

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
namespace DesignPattern
{
    class Program
    {
        //Find Even Number
        static void Main(string[] args)
        {
            int mulitplyby = 2;
            Func<int, int> operation = x => x * mulitplyby;
            Func<string, string> Concationation = x => x + "Kayal";
 
            Console.WriteLine("Multiple of 2 is= " + operation(2));
            Console.WriteLine("FullName is := " + Concationation("Sourav"));
            Console.ReadLine();
        }
    }
}

Conclusion:-

In this article we have seen how to use lambda expression in various ways. Hope you have enjoyed this article.