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Postings from May 2003
On Sun, May 18, 2003 at 03:18:04AM +0200, Slaven Rezic wrote:
> > print "increasing a to 1\n" if ($a++);
> > print "increasing a to 2\n" if ($a++);
> > ----------------------------------------------------------------------
> > i.e. if trying to increase zero-valued (or undefined) scalar the
> > result is always false if using '++' operator.
> > below is perl -V from my system. i also tried it on 5.005_03 and it
> > worked the same manner.
>
> This works as expected, because $var++ is the post increment operator.
> If you want pre increment, then use ++$var instead.
To clarify, post-increment means the value is checked and *then* its
incremented. Like:
if( $a ) {
print "increasing a to 1\n";
}
$a += 1;
useful for things like:
do_something_once unless $Done_Something++;
instead of:
unless( $Done_Something ) {
do_something_once;
$Done_Something += 1;
}
To make your example work the way you expected, use ++$a (pre-increment).
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