❔ => operator
So I read while looking into LINQ documentation that
=> is the syntax for a lambda expression. Now in the context of LINQ it makes sense, I would've guessed already. However in a class:
I would assume it is not seen as a lambda, it should just be a class method as its just syntax sugar for:
14 Replies
this is referred to as expression body syntax
so when its not declared to a name
like with
foo hereright, the meaning depends on the context
you can also declare lambdas outside of linq fwiw
for example
Action myAction = () => { do something; };Action is the base type for any Lambda i assume?
() captures any values you pass when calling the lambda
I assume it works similarly to a functionno,
Action is a delegate type which is sort of a function pointer if you're familiar with C/C++, it specifically represents a function that has no parameters and returns nothing
but yes, lambdas are simply functions with no name
the left side of the => is the parameter list, captures are automatic(you can use
static to avoid implicit captures)yes, in this case, it is an "expression-bodied member" https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/statements-expressions-operators/expression-bodied-members
Expression-bodied members - C# Programming Guide - C#
Learn about expression-bodied members. See code examples that use expression body definition for properties, constructors, finalizers, and more.
so:
std::function essentially, with a bunch of overhead. Do they offer raw function pointers or is this all available to us in C#?
they arent a class/struct under the hood that overload operator() like lambda's in C++?i haven't tried to use raw function pointers but if they exist you won't be able to use them outside of
unsafe blocks of code
no, lambdas are compiled as a method in the type they're declared in with an unspeakable compiler-generated name
with an additional class to contain captures if anything is captured
(i think, this isn't something i really have to pay attention to in my current projects)SharpLab
C#/VB/F# compiler playground.
Technically yes, but jimmacle is right, they're only usable in unsafe code and should be avoided by most people
Thanks all, makes sense!
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