Question

I am looking for a very simple – basic – no hardcore programming mumbo jumbo, simply put a generalized overview of a Lambda Expression in layman’s terms.

Answer 1

A lambda expression is, simply put, a re-useable expression which takes a number of arguments:

x => x + 1;

The above expression reads “for a given x, return x + 1”.

In .NET, this is powerful, because it can be compiled into an anonymous delegate, a nameless function you can declare inline with your code and evaluate to get a value:

int number = 100;

Func<int, int> increment = x => x + 1;

number = increment(number); // Calls the delegate expression above.

However, the real power of a lambda expression is that it can be used to initialize an in-memory representation of the expression itself.

Expression<Func<int, int>> incrementExpression = x => x + 1;

This means that you can give that expression to something like LINQ to SQL and it can understand what the expression means, translating it into a SQL statement that has the same meaning. This is where lambdas are very different from normal methods and delegates, and normally where the confusion begins.