extracting number from string

samuelalfred has asked for the wisdom of the Perl Monks concerning the following question:

Hello,

I have a string that looks for instance like this "Price 15.40". I want to extract the number out of that string resulting in 15.40. I have tried the following:

$string=~s/\D//g

which removes all "non-digit" characters from the string. However, then is also the decimal point "." removed which means that the result is 1540.

So my question is how to make this expression remove all "non-digit" characters EXCEPT . and ,?

Thanks!

Comment on extracting number from string

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Re: extracting number from string by moritz (Cardinal) on Mar 05, 2009 at 09:33 UTC
`s/[^.\d]//g`	[reply] [d/l]
Re: extracting number from string by Anonymous Monk on Mar 05, 2009 at 09:35 UTC
`=~ s/[^\d.]//g;` or you can borrow regex from How do I determine whether a scalar is a number/whole/integer/float?	[reply] [d/l]
Re^2: extracting number from string by samuelalfred (Sexton) on Mar 05, 2009 at 10:33 UTC
Thank you, but this doesn't quite do what I want. If $number = "Price 15.40", the result from $number=~s/^\D.//g is $number = ice 15.40 Any idea how to get this to be just 15.40? Thanks!	[reply]
Re^3: extracting number from string by puudeli (Pilgrim) on Mar 05, 2009 at 10:39 UTC
You copied the regex incorrectly. `perl -e '$n = "Price 15.40"; $n =~s/[^\d.]//g; print "$n\n";'` [download] Produces `15.40` [download] -- `seek $her, $from, $everywhere if exists $true{love};`	[reply] [d/l] [select]
Re^4: extracting number from string by samuelalfred (Sexton) on Mar 05, 2009 at 12:54 UTC
Re^5: extracting number from string by johngg (Canon) on Mar 05, 2009 at 14:03 UTC
Some notes below your chosen depth have not been shown here
Re: extracting number from string by johngg (Canon) on Mar 05, 2009 at 11:45 UTC
Alternatively, use a regular expression capture. `$ perl -le ' $str = q{Price 15.40}; ( $str ) = $str =~ m{(\d+\.\d+)}; print $str;' 15.40 $` [download] I hope this is useful. Cheers, JohnGG	[reply] [d/l]
Re^2: extracting number from string by apl (Monsignor) on Mar 05, 2009 at 12:40 UTC
For the general case, I'd replace `m{(\d+\.\d+)}` with `m{(\d+\.?\d+)}`, just in case a period is not specified in the price.	[reply] [d/l] [select]