in reply to Re^2: grep flip flop (range operator)
in thread grep flip flop (range operator)
perl -E 'say "Yes!" if $. == 0;'
$. uninitialized if there's no file open for reading (undef). undef is false. In a numeric comparison, undef is promoted to zero (or conceptually better, zero is demoted to false, and undef is promoted to false). Consequently, 0 .. is true, and the flip flop flips.
If warnings were enabled you'd get one. :)
Dave
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Re^4: grep flip flop (range operator)
by frozenwithjoy (Priest) on Sep 13, 2012 at 07:26 UTC |
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