Difference between lambda expressions and anonymous methods - C# [duplicate]

Answer 1

A lambda expression is simply shortcut syntax for an anonymous method. Anonymous methods look like this:

delegate(params) {method body}

The equivalent lambda expression would look like this:

params => method body

In short, all lambda expressions are anonymous methods, but it is possible to have an anonymous method that is not written in lambda syntax (like the first example above). Hope this is helpful!

Answer 2

Only lambda expression without method body can be converted to expression tree

Following constructs do compile:

            Func<int> exp1 = () => 1;
            Func<int> exp2 = () => { return 1; };
            Func<int> exp3 = delegate { return 1; };
            Expression<Func<int>> exp4 = () => 1;

And following do not

Expression<Func<int>> exp5 = delegate { return 1; }; //no anonymous delegates
Expression<Func<int>> exp6 = () => { return 1; }; //or lambdas with block body

So there is difference even on not very advanced level ( that Jon Skeet points out here sick difference example )

Another difference is that you can create anonymous delegates without parameter list if you don't plan to use them inside method body, with lambda you always have to provide parameters.

Following two lines demonstrate the difference

Func<int, int, int, int, int> anonymous = delegate { return 1; };
Func<int, int, int, int, int> lambda = (param1, param2, param3, param4) => 1;

You do essentially the same thing but anonymous delegate clearly looks better here.

Answer 3

Not really no. They are essentially the exact same feature with different syntax constructs. The general shift appears to be away from the C# 2.0 anonymous method syntax towards the lambda style syntax for both anonymous expressions and functions though.

Answer 4

Lambda expressions can be converted to expression trees, while anonymous delegates cannot.