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| author | Nicholas Clark <nick@ccl4.org> | 2000-12-11 01:48:38 +0000 |
|---|---|---|
| committer | Jarkko Hietaniemi <jhi@iki.fi> | 2000-12-11 15:09:11 +0000 |
| commit | 7d3a9d88333294f7510d5755825d4f26422ffba1 (patch) | |
| tree | 07009430453a017e64816d3474a8b7720e18df79 /pod/perlop.pod | |
| parent | 1f5346dc23a1f0ea577a0a8dfa3e9472d228092d (diff) | |
| download | perl-7d3a9d88333294f7510d5755825d4f26422ffba1.tar.gz | |
docs on NaN
Message-ID: <20001211014838.B99205@plum.flirble.org>
p4raw-id: //depot/perl@8078
Diffstat (limited to 'pod/perlop.pod')
| -rw-r--r-- | pod/perlop.pod | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/pod/perlop.pod b/pod/perlop.pod index 70fef4565b..0bb506ddc7 100644 --- a/pod/perlop.pod +++ b/pod/perlop.pod @@ -300,8 +300,13 @@ to the right argument. Binary "<=>" returns -1, 0, or 1 depending on whether the left argument is numerically less than, equal to, or greater than the right argument. If your platform supports NaNs (not-a-numbers) as numeric -values, using them with "<=>" (or any other numeric comparison) -returns undef. +values, using them with "<=>" returns undef. NaN is not "<", "==", ">", +"<=" or ">=" anything (even NaN), so those 5 return false. NaN != NaN +returns true, as does NaN != anything else. If your platform doesn't +support NaNs then NaN is just a string with numeric value 0. + + perl -le '$a = NaN; print "No NaN support here" if $a == $a' + perl -le '$a = NaN; print "NaN support here" if $a != $a' Binary "eq" returns true if the left argument is stringwise equal to the right argument. |