问题
In a new C# 6.0 we can define methods and properties using lambda expressions.
For instance this property
public string Name { get { return First + " " + Last; } }
can be now defined as follows:
public string Name => First + " " + Last;
The information about expression-boided function members you can find here: http://blogs.msdn.com/b/csharpfaq/archive/2014/11/20/new-features-in-c-6.aspx
Does anyone know if there's any overhead when using new syntax? Can it slow down (or improve efficiency of) the application or maybe it doesn't matter?
回答1:
In a new C# 6.0 we can define methods and properties using lambda expressions.
No, you can't. You can define method and property bodies using syntax which looks like a lambda expression, in that it uses the token =>.
However, importantly this does not mean that there's a delegate type involved. (Whereas a lambda expression is only permitted in a context where it's converted to an expression tree or delegate type.)
This is purely syntactic sugar. Your two example code snippets will compile to the exact same IL. It's just a different way of representing the body of a property getter or method.
回答2:
They will compile down to the same IL, you can always test this yourself by doing it and using ildasm to extract the IL.
来源：https://stackoverflow.com/questions/28411335/expression-bodied-function-members-efficiency-and-performance-in-c-sharp-6-0