http://www.perlmonks.org?node_id=768042


in reply to Re: Operator Associative in Perl
in thread Operator Associative in Perl

Perl doesn't define when the variable is incremented or decremented. [...] Perl will not guarantee what the result of the above statements is.

While operand evaluation order isn't documented, the order is the same in all versions on all platforms (intentionally), and changing it would break a lot of code.

perl always evaluates operands from left to right for left-associative operators and exponentiation (**), and from right to left for assignments operators.