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A lambda expression is an anonymous function and can be defined as a parameter. The Closures are like code fragments or code blocks that can be used without being a method or a class. It means that Closures can access variables not defined in its parameter list and also assign it to a variable.
All lambda expressions use the lambda operator =>, which is read as "goes to". The left side of the lambda operator specifies the input parameters (if any) and the right side hold the expression or statement block. The lambda expression x => x * 2 is read "x goes to 2 times x." This reduced the no.
a function that can be treated as an object is just a delegate. What makes a lambda a closure is that it captures its outer variables. lambda expressions converted to expression trees also have closure semantics, interestingly enough.
Lambda expressions in C# are used like anonymous functions, with the difference that in Lambda expressions you don't need to specify the type of the value that you input thus making it more flexible to use. The '=>' is the lambda operator which is used in all lambda expressions.
I usually say 'such that' when reading that operator.
In your example, p => p.Age > 16 reads as "P, such that p.Age is greater than 16."
In fact, I asked this very question on the official linq pre-release forums, and Anders Hejlsberg responded by saying
I usually read the => operator as "becomes" or "for which". For example,
Func f = x => x * 2;
Func test = c => c.City == "London";
reads as "x becomes x * 2" and "c for which c.City equals London"
As far as 'goes to' - that's never made sense to me. 'p' isn't going anywhere.
In the case of reading code to someone, say, over the phone, then as long as they're a fellow C# programmer, I'd just use the word 'lambda' - that is, "p lambda p dot age greater-than sixteen."
In comments Steve Jessop mentioned 'maps to' in the case of transformations - so taking Anders' example:
x => x * 2;
would read
x maps to x times 2.
That does seem much closer to the actual intention of the code than 'becomes' for this case.
From MSDN:
All lambda expressions use the lambda operator =>, which is read as "goes to".
Reading Code Over the Telephone
From Eric Lippert:
I personally would say c=>c+1 as "see goes to see plus one". Some variations that I've heard:
For a projection, (Customer c)=>c.Name: "customer see becomes see dot name"
For a predicate, (Customer c)=>c.Age > 21: "customer see such that see dot age is greater than twenty-one"
I've always called it the "wang operator" :-)
"p wang age of p greater than 16"
I've seen people say, "Arrow."
I use "goes to" because a LINQ book told me to :)
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