Delegates, Lambdas, Action, Func, Anonymous Functions

Question

I just want to verify my understanding about the following

• Delegate - a method signature
• Lambdas - anonymous function
• Anonymous Function - just that
• Action - An anonymous function that returns nothing
• Func - An anonymous function that returns something

hmm... they all do similar things, how do you define & know when to use each?

sorry, I don't explain well

Answer 1

• Delegate - it is not a method signature. It is a type which encapsulates a method. Hence a delegate declaration should have a signature similar to the method it wants to encapsulate. When to use Delegate - whenever you want to pass a method to another function. For more see this and this.

• Lambdas - short hand and more expressive way of writing an anonymous function. But there is more to it. A lambda expression can also be converted to an expression tree. For more see this.

• Anonymous Function - yes .. just that

• Action - It is a delegate which can encapsulate a function that returns nothing. So you should think of it as a type that can encapsulate an action and use it when you need to pass an action around.

• Func - A delegate that can encapsulate a function that returns something. But you should look at it as a type that can encapsulate a transformation and use when you want to pass around a transformation.