Reputation: 2025
I read this interesting line here, in an answer by Jon Skeet.
The interesting line is this, where he advocated using a delegate:
Log.Info("I did something: {0}", () => action.GenerateDescription());
Question is, what is this ()=> operator, I wonder? I tried Googling it but since it's made of symbols Google couldn't be of much help, really. Did I embarrassingly miss something here?
Upvotes: 46
Views: 43439
Reputation: 101
=>
this is lambda operator. When we don't have any input parameters we just use round brackets ()
before lambda operator.
syntax:
(input parameters) => expression
Upvotes: 10
Reputation: 3565
It's way to pass anonymous delegate without parameters as lambda expression.
Similar to this from .NET 2.0
Log.Info("I did something: {0}", delegate()
{
return action.GenerateDescription();
});
Upvotes: 3
Reputation: 11608
This introduces a lambda function (anonymous delegate) with no parameters, it's equivalent to and basically short-hand for:
delegate void () { return action.GenerateDescription(); }
You can also add parameters, so:
(a, b) => a + b
This is roughly equivalent to:
delegate int (int a, int b) { return a + b; }
Upvotes: 68
Reputation: 27717
This is an example of a lambda expression you can learn more here.
Upvotes: 3
Reputation: 100258
Creating an anonymous delegate to specified method.
Probably, in your case it will be a Func<string>
Upvotes: 3