Assignment and mutation

New to Julia
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The simplest version of this I can come up with is this:

  • Assignment changes which object a name refers to: x = ex causes the name x to refer to the value resulting from the evaluation of the expression ex. Assignment never changes the values of any objects.

  • Mutation changes the value of an object: x[i] = ex and x.f = ex both mutate the object referred to by x changing a value at index or a property with a name, respectively. Mutation never changes what objects any names in any scope refer to.

Perhaps the confusion comes from the fact that these all use the = in their syntax? They’re really totally unrelated. It’s also possible that people think of assignment as setting a named property on some implicit “scope object”. That’s probably a view that can be worked out coherently, in which case having a clear notion of what all the different “scope objects” are would be crucial but I’m not entirely sure if that’s a helpful way to think about the matter or not.

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