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Discussion on: Weird behaviors of javascript: Primitive Types and Reference Types

 
pentacular profile image
pentacular • Edited

Could you be more specific about the confrontational style that you perceive?

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willsmart profile image
willsmart

A bit of constructive editing...

I'm glad we can all agree that javascript doesn't support pass by reference.

Now, could you show me where in the ecmascript standard it talks about an object value being a reference?

vvvvvv

(First para deleted)

What do you mean that object values are references? I've been fishing through the spec (ecma-international.org/ecma-262/11...) and can't find anything saying so.

Same info and questions, but the second one is showing you're willing to put in some work to find your answer, that we probably fundamentally agree but are stuck on terminology, and will ultimately avoid nag replies like this.
If the language doesn't come naturally to you, try your best to fake it til you make it.

I had a squiz at the spec, couldn't find a specific mention, and ran out of motivation to dig further. The proof though is

a = {}
b = a
a.foo = 1
console.log(b.foo) // <- prints "1"

For a time, the values of a and b refer to the same object. They hold two pointer-like structures that reference the same shared underlying object. In programming this is often called a reference.

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willsmart profile image
willsmart

I'm signing off the thread btw

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pentacular profile image
pentacular • Edited

That's fine, but for future reference, let's note that a.foo doesn't mean that a is a reference.

It does mean that a and b have the same value, and it does mean that that value is used to find a particular property named 'foo' and modify that.

Which makes me think that all of this 'reference' stuff is something someone made up to try to explain javascript in terms of a language with references, like C++, but which doesn't quite fit.