Re: Map Function Weirdness

I, also, am a bit unsure of the real question of rthawkcom.

However, if it has to do with the fact that the @out array has all the values of the %hash when $_; is the last statement executed in the map block and has a few empty strings in place of hash values when $_; is not the last statement, I think I can explain.

The value of the map block on each iteration will be the value of the last expression evaluated in the block. This is always the $_ expression, previously set to a hash value, when the $_; statement is last.

When the
if($_>$max){$max=$_}
statement is last, $_>$max will be the last expression evaluated when $_ is less than or equal to $max (and it will evaluate to the empty string, or false).

When $_ is greater than $max the $max=$_ true clause of the statement will execute, which evaluates to $_ previously set to a hash value.

Update: This reply is essentially the same as jethro's.

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Re^2: Map Function Weirdness by ikegami (Patriarch) on Nov 08, 2011 at 22:01 UTC
and it will evaluate to the empty string Not quite. The comparison operators and possibly all operators returns triplevar(0, 0.0, "") for false. `$ perl -wE'say 0 + (0 > 1)' 0 $ perl -wE'say 0 + ""' Argument "" isn't numeric in addition (+) at -e line 1. 0` [download] which evaluates to $_ previously set to a hash value Not quite. Scalar assignment evaluates to its LHS, so it evaluates to `$max`, not `$_`. `$ perl -E'$_ = 123; ++( $max = $_ ); say $max; say $_;' 124 123` [download] Of course, they hold the same value at that point, and map promptly copies that value.	[reply] [d/l] [select]
Re^2: Map Function Weirdness by rthawkcom (Novice) on Nov 08, 2011 at 20:16 UTC
It is, but easier to follow. I voted you both up. Thanks for the fast help!	[reply]