C# Syntax – What Does ‘() =>’ Mean?

Basically it's specifying an anonymous function, that takes no parameters that calls SomeAction. So yes, they are functionally equivalent. Though not equal. Using the lambda is more equivalent to:

del = new SomeDelegate(this.CallSomeAction);

where CallSomeAction is defined as:

public void CallSomeAction()
{
    this.SomeAction();
}

Hope that helps!

In C# the lambda operator is written "=>" (usually pronounced "goes to" when read aloud). It means that the arguments on the left are passed into the code block (lambda function / anonymous delegate) on the right.

So if you have a Func or Action (or any of their cousins with more type parameters) then you can assign a lambda expression to them rather than needing to instantiate a delegate or have a separate method for the deferred processing:

//creates a Func that can be called later
Func<int,bool> f = i => i <= 10;
//calls the function with 12 substituted as the parameter
bool ret = f(12);