Extract One of Several Numbers from a String

Question

Let's say I've got something like:

{values="99999" name="22222" store="11111"}

with:

.match(/values="\d+/) 

would return:

values="99999

How can I get just the "99999" out of it?

I've tried

.match(/values="(\d+)/) 

which should return just the numbers I thought, but it doesn't.

Hope someone can help!

Cheers,

Answer 1

Try this regex,

.match(/values="(\d+)"/) 

For just only the number after values= , you could use look-behind and look-ahead

.match(/(?<=values=")(\d+)(?=")/) 

Explanation:

• (?<=values=") Look-behind is used here. It sets the matching marker just after to the string values="
• (\\d+) In regex () called capturing groups. It captures one or more digits.
• (?=") Lookahead is used to check whether the following character after the digits is double quotes or not. If it's double quotes then only the preceeding digits would be matched.

Answer 2

Ruby 2+: Use \\K

Do this:

if subject =~ /values="\K\d+/
    match = $&

• values=" matches literal characters
• The \\K tells the engine to drop what was matched so far from the final match it returns
• \\d+ matches your digits

Answer 3

If you use the .captures method and look inside the return value, you will find what you need.

#!/usr/bin/env ruby

string = '{values="99999" name="22222" store="11111"}'
one = string.match(/values="(\d+)/).captures

p one   => ["99999"]

Answer 4

Basing from everyone's answer I can also suggest adding .to_a.shift which would return the found value if found or nil if not. Example:

.match(/(?<=values=")(\d+)(?=")/).to_a.shift
.match(/values="\K(\d+)/).to_a.shift

Doing rescue nil may also apply but it's a little hacky or less safe.