On Sat, 1 Dec 2001, linkagent wrote:
> ----- Original Message -----
> From: "$Bill Luebkert" <[EMAIL PROTECTED]>
> To: "linkagent" <[EMAIL PROTECTED]>
> > linkagent wrote:
> > > I need members help on this;
> > > Q1) As far as I know, \d* means match either 0 or more digits, since
> > > /(\d*)/ match 1006326869812 , therefore
> > > I could not see how /(\d*)(\d{4})(\d{5})/) could seperate 1006326869812
> into
> > > (1006)(3268)(69812)
> >
> > The last two parts of the regex pick up 4 and 5 digits resp. The first
> > picks up all the rest since it's 0 or more. Obviously some back-tracking
> > has to occur since the first length is unknown. It might be faster to
> > anchor the back end:
> > /(\d*)(\d{4})(\d{5})$/
>
> Correct me if I am wrong;
> Therefore am I right to say that the matching sequence starts from the back
> first (which is not what I read from the books about matching / /).
>
> i.e in the following match /(\d*)(\d{4})(\d{5})$/
> the regexes look for $ first;
> then followed by (\d{5}) ;
> then followed by (\d{4})
> then (\d*)
>
> > > Q2) Out of curiosity, I tried the undermentioned but I could not
> > > understand why on the 3rd iteration it print only 3 instead of
> > > 35968322963568389 :-
> > >
> > > for $number (1006326869812, 563296853235993 , 35968322963568389){
> > > print "$1\n" if ($number =~ /(\d*)/);
> > > }
>
> > The third number is too large to express as an integer.
> > Try putting quotes around it so it's treated as a string.
>
> I thought if the number is too large, it will display something like this
> 3e0whatever-number, nevertheless, I will read on this.
>
Which may explain why the last number matched only on the leading 3 digit.
To find out for sure, the print statement could be changed to:
print "$1 number=$number\n" if $number=~/(\d*)/;
Actually on my PC the third number printed out as: 3.59683229635684e+016
Note that the character in the second-most significant position of the
mantissa is the "." character which doesn't match the \d* regex pattern.
Bill's suggestion to surround the numbers with quotes will allow the
entire string of digits to match.
**** [EMAIL PROTECTED] <Carl Jolley>
**** All opinions are my own and not necessarily those of my employer ****
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