Description:
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The documentation for array operators currently says this:

> $a + $b 	Union 	Union of $a and $b.

At least to me, this signals that if I apply this operator on two arrays (e.g. [1, 2] and [3, 4, 5, 6]), I would get an array which holds all elements appearing in each array: [1, 2, 3, 4, 5, 6]. But that's not what I get. Instead, I get [1, 2, 5, 6], as documented in a note below the initial table:

> The + operator returns the right-hand array appended to the left-hand array; for 
> keys that exist in both arrays, the elements from the left-hand array will be 
> used, and the matching elements from the right-hand array will be ignored. 

as well as in a set of examples below.

I believe it's wrong to refer to this operation as simply union, thus I suggest to change the documentation to make it more obvious upfront.


I don't have a good idea how to reword it exactly ATM, but perhaps just changing "Union" to "Union by keys" in the table would be enough?