Question

Can anybody help me write a regular expression which could find all the instances of the following in a long string >

type="array" count="x" total="y"

where x and y could be any numbers from 1 to 100.

language is ruby.

Answer 1

First, since we’ll use the regex for a number twice, we’ll save it as its own variable. Note that the number regex is comprised of three separate pieces: one-digit numbers, two-digit numbers, and three-digit numbers. This is a good rule of thumb to use when trying to make a regex to match a range of numbers. It’s easy to get it wrong otherwise (allowing strings like "07").

Once you have the number regex, the rest is easy.

number = /[1-9]|[1-9][0-9]|100/
regex  = /type="array" count="#{number}" total="#{number}"/
string.scan(regex)