delegate operator (C# reference)

The delegate operator creates an anonymous method that can be converted to a delegate type:

Func<int, int, int> sum = delegate (int a, int b) { return a + b; };
Console.WriteLine(sum(3, 4));  // output: 7

Beginning with C# 3, lambda expressions provide a more concise and expressive way to create an anonymous function. Use the => operator to construct a lambda expression:

Func<int, int, int> sum = (a, b) => a + b;
Console.WriteLine(sum(3, 4));  // output: 7

When you use the delegate operator, you might omit the parameter list. If you do that, the created anonymous method can be converted to a delegate type with any list of parameters, as the following example shows:

Action greet = delegate { Console.WriteLine("Hello!"); };

Action<int, double> introduce = delegate { Console.WriteLine("This is world!"); };
introduce(42, 2.7);

// Output:
// Hello!
// This is world!

That's the only functionality of anonymous methods that is not supported by lambda expressions. In all other cases, a lambda expression is a preferred way to write inline code. For more information about features of lambda expressions, for example, capturing outer variables, see Lambda expressions.

You also use the delegate keyword to declare a delegate type.

C# language specification

For more information, see the Anonymous function expressions section of the C# language specification.

See also