Re:The melting pot of JavaScript (2017)
by stickfigure on Monday January 07, 2019 @11:45PM
(#18853215)
Yes, you are correct. There are also a number of circumstances in which you can get generic type info - it isn't erased, for example, if you create a concrete subclass of a generic type.
I was talking about JavaScript. In JavaScript there are no typed functions or arguments, so that information doesn't exist period.
Right, so I guess I'm not understanding your point about why comparing two languages like this is ridiculous. Java has a full blown runtime reflection system (it's "types exist at runtime"). JS doesn't. So Java wins in the reflection category.
Re:The melting pot of JavaScript (2017)
by tracker1 on Tuesday January 08, 2019 @03:43PM
(#18859479)
But in JS, reflection is pretty much not needed... I don't need to use reflection to see if an object has a quack method, or that I call it with the right types... I just call instance.quack() ... It's up to you as the developer to keep your interfaces and composition in line.
It's actually WAY easier than with C# or Java. Since the use-case of reflection itself is largely unnecessary.
Correct if I'm wrong, not all types get erased in Java. Doesn't type erasure only happen for generics? Say I have a non generic, plain Java class and want to inspect one of it's method's return types at runtime to see if it returns class A or class B. I can do that, right?