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What's worth nothing, nowadays most of the concepts "that are too hard for web developers" In the quote are already part of frontend programming. Concurrency -

What's worth nothing, nowadays most of the concepts "that are too hard for web developers" In the quote are already part of frontend programming. Concurrency - web workers Compilers - technically you can write compiler, but it's a very specific use case and I think that web is simply not a proper platform for writing them usually 3d - webgl Class inheritance - classes in js (they're not identical to i.e. Java classes but they provide a very similar abstraction on the first glance) Abstract classes - Typescript has it Pass by value vs pass by reference - something that js programmers had to always understand in the past for the sake of handling primitives and objects in js Garbage collection - weak references in js Software development methodologies depend highly on team

chakkepolja 5y ago
> Pass by value vs pass by reference - something that js programmers had to always understand in the past for the sake of handling primitives and objects in js. Noob question. Aren't primitives immutable? Does it need distinguishing between Value & ref types?
- pornel 5y ago
  Compare: function(x) { x += 1; } function(o) { o.x += 1; } The first one behaves like passing by value, the second like passing by reference. Under the hood the `Number` x may have been passed by reference and changed by creating a copy, or it may have been JITed to be an i32 actually passed by value, or optimized out of existence entirely. How it is actually passed ends up being an implementation detail that you can't observe from high-level perspective.
- Byamarro 5y ago
  Objects are always treated as a reference, primitives as a value. To say they're immutable requires a bit more of a context - immutable in what sense? You can reassign a different value to a variable that stores a primitive, so it's not like variables that store them are immutable. I guess that the simpliest explanation would be by code: let x = 4 let z = x z = w // x is still 4 let x = { b: 3 } let z = x z.b = 2 // x is { b: 2 }, because x and z hold reference to the same object

chakkepolja 5y ago

> Pass by value vs pass by reference - something that js programmers had to always understand in the past for the sake of handling primitives and objects in js. Noob question. Aren't primitives immutable? Does it need distinguishing between Value & ref types?

pornel 5y ago
Compare: function(x) { x += 1; } function(o) { o.x += 1; } The first one behaves like passing by value, the second like passing by reference. Under the hood the `Number` x may have been passed by reference and changed by creating a copy, or it may have been JITed to be an i32 actually passed by value, or optimized out of existence entirely. How it is actually passed ends up being an implementation detail that you can't observe from high-level perspective.
Byamarro 5y ago
Objects are always treated as a reference, primitives as a value. To say they're immutable requires a bit more of a context - immutable in what sense? You can reassign a different value to a variable that stores a primitive, so it's not like variables that store them are immutable. I guess that the simpliest explanation would be by code: let x = 4 let z = x z = w // x is still 4 let x = { b: 3 } let z = x z.b = 2 // x is { b: 2 }, because x and z hold reference to the same object