Can someone explain where Lambda Expressions would be useful?

[winlonghorn]

I was wondering what the benefits of using Lambda Expressions are. Can someone think of examples of where they would be beneficial to use? Let's say that I have a website where I want to add and manipulate customer and product information from a database. Is that a good place to use them for instance? Thank you in advance!

[Andre S. Veteran]

Lambdas are more than inline functions, they are also closures. Any lambda that captures local variables, fields, etc, is compiled not to a method but to a type. C++ programmers are familiar with this concept under the name of functors; it was the only way to do closures before the advent of lambda expressions in C++11. C# had support for closures before lambdas actually, in C# 2.0 there were already anonymous methods which are basically lambdas with an ugly syntax. With lambdas, LINQ and the Func and Action types, C# 3.0 made functional programming much easier.

[Xilo]

Lambda expressions are good for one off items that require a function but not necessarily need a full blown function created.

 

One use could be finding an object within a list that contains a certain value for one of it's member attributes.

[winlonghorn]

Ok, so it would be good for searching for information / generating a report on one specific product basically?

[threetonesun]

Yes, see the wikipedia entry for some good examples: http://en.wikipedia.org/wiki/Lambda_%28programming%29#Sorting

 

If you're referring to them in the more general sense of being anonymous functions, then they get thrown all over in Javascript.

[winlonghorn]

Ok, I will take a look. Thank you!

[francescob]

Ok, so it would be good for searching for information / generating a report on one specific product basically?

 

Just like for anonymous functions it's just to avoid flooding classes with methods with the most basic functionalities.

[winlonghorn]

Oh ok! That makes it a lot clearer! I can definitely see now how using Lambdas would be useful instead of having tons of small methods all over the place. That is exactly what I was looking for (the reason they were created). Thank you!

[winlonghorn]

Oh ok, so they can function as classes as well then?

[Andre S. Veteran]

Oh ok, so they can function as classes as well then?

In the very limited sense that they can capture local state (fields, local variables, etc), yes. I suggest you look at the Jon Skeet article I linked to get a better understanding of closures.

[winlonghorn]

Thank you! I will be sure and have a look. :)