Re: Need to match number other than 1
by tachyon-II (Chaplain) on Nov 29, 2007 at 10:22 UTC
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if ( $number =~ m/^\d+$/ and $number != 1 ) {
# do stuff
}
else {
die "There can be only 1!"
}
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Re: Need to match number other than 1
by moritz (Cardinal) on Nov 29, 2007 at 10:28 UTC
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m/\A
(?:
[1]\d+ # if it starts with a 1,
# it has to be followed by other digits
|
[023456789]\d* # otherwise one digit can be fine
)
\z
/x
Note that this matches only non-negative integers, and 01 is matched as well (no idea if that's OK or not, spec is unclear).
Note that you need some kind of anchoring (perhaps to a word boundary), but you don't necessarily need to anchor it to start and beginning of the string. | [reply] [d/l] [select] |
Re: Need to match number other than 1
by shmem (Chancellor) on Nov 29, 2007 at 10:19 UTC
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I need to match a number other than 1.
So you started with matching 1 ? How did you do that?
Read perlre. While you're at it, read How (Not) To Ask A Question, then post the code you tried.
--shmem
_($_=" "x(1<<5)."?\n".q·/)Oo. G°\ /
/\_¯/(q /
---------------------------- \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
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Am I missing the point here or isnt it just
if($number != 1) {
}
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qwurx [shmem] ~ > perl -wle '$foo = "bar"; print "not 1" if $foo != 1'
Argument "bar" isn't numeric in numeric ne (!=) at -e line 1.
not 1
--shmem
_($_=" "x(1<<5)."?\n".q·/)Oo. G°\ /
/\_¯/(q /
---------------------------- \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}
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Re: Need to match number other than 1
by grinder (Bishop) on Nov 29, 2007 at 10:35 UTC
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if ($num =~ /^[^\D1]\d+$/) {
print "does not begin with a 1\n";
}
The key to understanding this is that you are looking for anything that is not a non-digit or a 1. When you negate the negations in the above phrase, you'll see that it means you're matching 0, 2-9.
uh, update: that doesn't quite work, hang on a sec...
if ($num =~ /^(?:[^\D1]|1\d)\d*$/) {
print "not a 1\n";
}
2nd update: now it works. It is instructive to see how the pattern had to be modified to exclude 1, but allow 10, 19, 1111, ...
• another intruder with the mooring in the heart of the Perl
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That doesn't match any single digit number, nor will it match 10, which is not 1 either.
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Re: Need to match number other than 1
by mwah (Hermit) on Nov 29, 2007 at 13:02 UTC
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I need to match a number other than 1. The input can be even four or five digit. But it should allow when it is not number 1
After trying to interpret your question (what is meant by "number 1" anyway), I'll
add another version of the "detection of 1 game":
...
my $num1 = qr{^ (?> ([\.\d]+) ) (??{$1 == '1' ? '(?!)' : '' }) }x;
my $txt1 = qr{^ (?> ([\.\d]+) ) (??{$1 eq '1' ? '(?!)' : '' }) }x;
my @stuff = qw' 0101 1 123 1.1 01 222 21 1.000 ';
print
map $_
. "\t as num: " . (/$num1/ ? 'ok' : '--')
. "\t as txt: " . (/$txt1/ ? 'ok' : '--')
. "\n",
@stuff;
...
Regards
mwa | [reply] [d/l] |
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You don't have to generate any code. The (?(COND)TRUE|FALSE) assertion fits the glove here. $^N can be used instead of $1 here, making it copy-paste safe.
I'd also like to draw some attention to Regexp::Common::number. These changes would make
my $num1 = qr{^ (?> ([\.\d]+) ) (??{$1 == '1' ? '(?!)' : '' }) }x;
become
use Regexp::Common qw/ number /;
my $num1 = qr{^ (?> ($RE{num}{dec}) ) (?(?{ $^N != '1' })|(?!)) }x;
I reversed the logic in the COND block so that it reads better to me. "Match a number, the number isn't 1, done".
lodin | [reply] [d/l] [select] |
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I tried that and got this warning:
Argument "\x{d6d}\x{bef}" isn't numeric in numeric eq (==) at (re_eval
+ 2) line 1.
:)
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Re: Need to match number other than 1
by GrandFather (Saint) on Nov 29, 2007 at 10:46 UTC
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if ($theNumberUnderTest == 42) {
print "Matched a number other than 1\n";
}
Perl is environmentally friendly - it saves trees
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Yeah, I'd have to say this answers the "question" by testing for the ultimate answer, to life, the universe, and everything; but what was the question?
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Re: Need to match number other than 1
by tcf03 (Deacon) on Nov 29, 2007 at 12:58 UTC
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if ( $number =~ /^\d*$/ and $number != 1 )
{
# not 1 stuff here
}
Ted
--
"That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved."
--Ralph Waldo Emerson
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Re: Need to match number other than 1
by queldor (Acolyte) on Nov 29, 2007 at 13:46 UTC
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reading it as 'Need to match number other than 1 digit'
if( m{^\d{2,}$} ) {
# do stufff
}
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Re: Need to match number other than 1
by olus (Curate) on Nov 29, 2007 at 14:09 UTC
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Reading it as having a sequence of 4 or 5 digits, as in '12345', and allowing sequences that do not have the '1', then simply:
my $sequence = '12345';
if( index($sequence, '1') >= 0 ) {
# found the 1 digit. Interrupt here.
}
--
olus | [reply] [d/l] |
Re: Need to match number other than 1
by logan (Curate) on Nov 29, 2007 at 21:54 UTC
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Re: Need to match number other than 1
by nimdokk (Vicar) on Nov 29, 2007 at 20:23 UTC
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I don't know, this may be over-simplistic - but what about:
if ( $number > 1 ) {
print "$number greater than 1.\n";
} elsif ( $number < 1 ) {
print "$number less than 1.\n";
} else {
print "$number is 1.\n";
}
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Re: Need to match number other than 1
by hangon (Deacon) on Nov 30, 2007 at 08:49 UTC
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if ($number - 1){
#do sometning
}
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Re: Need to match number other than 1
by iomatrix (Initiate) on Nov 30, 2007 at 00:57 UTC
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Easier to ask if it isn't 1 then if it is.
if (not ($var == 1))
{
...do whatever...
}
Chris (iomatrix) | [reply] |
Re: Need to match number other than 1
by xicheng (Sexton) on Dec 01, 2007 at 08:37 UTC
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if ($str =~ /^(?!1$)\d+$/) {
do_stuff($str);
}
Regards,
Xicheng | [reply] [d/l] |