Does ActionScript3 have a function which can merge an array like in PHP?
array array_merge ( array $array1 [, array $array2 [, array $... ]] )
No, there isn't one built in, or part of the standard library.
A keyless set of arrays would be combined with array1.concat(array2);
But the key based merging feature of array_merge
isn't available. There's a set of Array utilities in the as3corelib
https://github.com/mikechambers/as3corelib (there's a method called ArrayUtil.createuniqueCopy()
which might be what you want in there.)