Re: [PerlChina] split function and zero-width seperator

perl -MData::Dumper -le '$a="15678.91 ml; r45.12 "; @a=grep !/^\s*$/, split /([\d\.]+)/, $a; print Dumper  \@a'

the regex pattern for split don't need to be that complicated. :-)

2009/10/23 tiger peng <tigerpeng2001@yahoo.com>

Hello everyone,

 

I am trying to isolate numbers from string, manipulate the numbers then put them back to original positions in the string. When I try to use zero-width separator, the split function looks weird, it generated much more elements than I expect.

 

Are there any mistakes? Why the split behaviors like this? (The regexp looks right when I used it s///)

 

Could anyone help?

 

Thanks,

Tiger

 

#build the seperator

:-) perl -le '$a = "15678.91 ml; r45.12 ";

              $a =~ s/((?!(\d|\.))(?<=(\d|\.)))|((?=(\d|\.))(?<!(\d|\.)))/|/g;

              print $a'
|15678.91| ml; r|45.12|

 

#use the seperator in split

:-) perl -MData::Dumper -le '$a = "15678.91 ml; r45.12 ";

                             @a = split /((?!(\d|\.))(?<=(\d|\.)))|((?=(\d|\.))(?<!(\d|\.)))/, $a;

                             print Dumper(@a)'
$VAR1 = '15678.91';
$VAR2 = '';
$VAR3 = undef;
$VAR4 = '1';
$VAR5 = undef;
$VAR6 = undef;
$VAR7 = undef;
$VAR8 = ' ml; r';
$VAR9 = undef;
$VAR10 = undef;
$VAR11 = undef;
$VAR12 = '';
$VAR13 = '4';
$VAR14 = undef;
$VAR15 = '45.12';
$VAR16 = '';
$VAR17 = undef;
$VAR18 = '2';
$VAR19 = undef;
$VAR20 = undef;
$VAR21 = undef;
$VAR22 = ' ';

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