For me it didn't really simplify programming, it just added mental overhead. Every array I used was either strictly sequential or strictly a mapping, and the language did nothing to help me keep track of that.
It also makes some potential niceties impossible. Python can give a special meaning to a negative index into a list, because it can never truly exist, but PHP has to treat it like a key and do a normal lookup.
It also makes some potential niceties impossible. Python can give a special meaning to a negative index into a list, because it can never truly exist, but PHP has to treat it like a key and do a normal lookup.