LAMBDA EXPRESSION IN C#

c# lambda expression 

LAMBDA EXPRESSION IN C#

“Lambda expression is just a short hand for write the anonymous method, means it is a simple method to write an anonymous method”.  Lambda expression is represented by => (Equal in sense of math and assignment operator in programming and then greater then operator) see the example for better understanding.

It will better understand if you have clear idea about anonymous method. In anonymous we taught about the removing of method defining and then binding with the delegate separately, simple and straight we defined and bound the unnamed method by the time of creating delegate instance. Like this

<Delegate-name> Obj = delegate (parameter list)

{

            Method implementation;

} ;

syntax of lambda expression is slightly change that is bellow.

Syntax of lambda expression

1.    It’s also included in three steps 1^st step define delegate under name space of same signature that would be the method signature.

2.    In 2^nd step using lambda expression define method and bind with thedelegate.

3.    And 3^rd step call the method using the name of delegate.

All the steps that included in anonymous method defining, calling and instance creating. Lambda expression syntax is also same like that but here by bringing a little bit change in anonymous method syntax of creating instance we will make the lambda expression syntax but the remaining two steps that include the defining of delegate under namespace and calling will still same. Have a look to the above anonymous method syntax and then see this

<Delegate-name> Obj = (parameter name) =>

{

            Method implementation;

} ;

We remove the delegate keyword and data type form the anonymous method and use => in place of that that makes the codding easier and time saving but it will work like anonymous method that’s why lambda is called as the short hand writing for anonymous method.

EXAMPLE OF LAMBDA EXPRESSION IN C#

            Suppose we have a method that accept name and generate some greeting with help of lambda expression

Main program

namespace LambMethod

{

    public delegate string GreetDelegate(string str);  //defining delegate stage 1

    class Program

    {

        static void Main(string[] args)

        {

            GreetDelegate Obj = (str) =>   //lambda expression defining stage 2

            {

                return "Hello " + str + " Welcome to Newmountain Hotel";

            };

            Console.WriteLine(Obj("Asif"));  //calling delegate/anonymous method S-3

            Console.ReadKey();

        }

    }

}