When to use Func, Action And Predicate Delegates

Question

Hi Friends. I just wanted to ask a question in regards to what areas or components in software architecture or development are best suited for using Func, Action And Predicate Delegates. Thanks for any articles or references to blogs.

Answer 1

they are used to implement a callback. callbacks are common in the following patterns (but not limited to)

Visitor Pattern: http://en.wikipedia.org/wiki/Visitor_pattern
Observer Pattern: http://en.wikipedia.org/wiki/Observer_pattern
Strategy Pattern: http://en.wikipedia.org/wiki/Strategy_pattern

Answer 2

@Ronald Rex , Welcome to Microsoft Q&A,

If you want to return one result with zero, one or more input parameters, you could use Func Delegate.

If you don't want to return result with zero, one or more input parameters, you could use Action Delegate.

If you want to return a bool type result with zero, one or more input parameters, you could use Predicate Delegate.

You could refer to the following links to know more about it.

Func vs. Action vs. Predicate

Delegates: Predicate vs. Action vs. Func

Best Regards,
Jack

---

If the answer is the right solution, please click "Accept Answer" and upvote it.If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.