Re: map confusion

$_++ is a post increment. The value used is the value $_ contained before being incremented. Unless there is a compelling reason to use the post increment operator you should always use the pre increment operator: ++$_.

Oh, and it's nothing to do with map!

Premature optimization is the root of all job security

Comment on Re: map confusion Select or Download Code

Replies are listed 'Best First'.
Re^2: map confusion by Anonymous Monk on Dec 15, 2015 at 23:53 UTC
Thank-you. However even with ++$_, @array is still affected in the first case, but not with *. Any thoughts on why?	[reply]
Re^3: map confusion by FreeBeerReekingMonk (Deacon) on Dec 16, 2015 at 00:04 UTC
Let's say you have a variable `$A` and you do this: `$A = 5; $B = $A++; print $A;` # prints out 6. $B is 5 `$A = 5; $B = ++$A; print $A;` # prints out 6. $B is 6 `$A = 5; $B = $A*2; print $A;` # prints out 5. $B is 10 `$A = 5; $B = $A+1; print $A;` # prints out 5. $B is 6 Because ++ changes the original AFTER the operation, and mutiplication just returns the result, without modifying the original.	[reply] [d/l] [select]