Is there a situation where the use of the lambda expression is particularly helpful or its mainly usage is to write less code?
+2
A:
Lambda expressions are syntactic sugar for anonymous methods, and their use cases are mostly the same.
Lambdas can also be converted to expression trees.
As they are much shorter and easier to write (at least for the simple cases), that in itself is helpful.
Oded
2010-02-27 15:24:27
I like the expression "syntactic sugar", I didn't know it.
Maurizio Reginelli
2010-02-27 15:26:25
Not *quite* the same - lambda expressions can also be converted into expression trees, whereas anonymous methods can't. (There's no such term as "anonymous delegate" - there are *anonymous methods*, and *anonymous functions* - that latter is a term covering both anonymous methods an lambda expressions.
Jon Skeet
2010-02-27 15:27:30
@Jon - Thanks for the correction. Answer updated.
Oded
2010-02-27 15:36:57
+1
A:
Take a look at John Skeet's SO answer here. And here is another SO question with specific uses of lambdas
David Robbins
2010-02-27 15:27:12
+17
A:
The justification for adding lambdas to the language was two things.
(1) They make syntactic transformation of query comprehensions possible. When you say
from customer in customers
where customer.City == "London"
select customer
That becomes
customers.Where(customer=>customer.City == "London")
(2) They can be turned into expression trees, and thereby make LINQ-to-SQL, LINQ-to-Entities, and so on, possible. That is, they can represent both the ability to do their semantics and the ability to inspect their structure.
Eric Lippert
2010-02-27 15:32:36
Could you provide an example of an expression tree, please? Thanks
Maurizio Reginelli
2010-02-27 15:49:23
@Maurizio: http://blogs.msdn.com/charlie/archive/2008/01/31/expression-tree-basics.aspx
Eric Lippert
2010-02-27 16:31:08