Which regex would fit better to extract the last 2 numbers separated by dot

e.g.

abc.98.76.xyz12.34 -> 12.34
qwer12.34.ty.98.76 -> 98.76

I tried \d (?!\d )\.\d (?!\d )$ but not sure if it's the best option.

CodePudding user response：

Possible solution is the following:

(\d \.\d )$

See explanation at regex101

if you need to specify exact qty of numbers:

(\d{2}\.\d{2})$

Where:
\d - any digit
  - one o more characters
\. - dot
{2} - exactly two characters
$ - end of string

CodePudding user response：

Here are two ways to do that.

If the string matches

.*(?<!\d)(\d \.\d )

the desired result will be held by capture group 1.

Demo

.* is greedy, so it will consume as many characters as possible, including digits and periods. The negative lookbehind (?<!\d) ensures that the last character matched by .* is not a digit. Without it, for the string 'abc12.34', .* would match 'abc1' and capture group 1 would contain '2.34'.

The other option is to match the regular expression

\d \.\d (?!.*\d \.\d )

which does not use a capture group.

Demo

The negative lookahead (?!.*\d \.\d ) ensures that the match is not followed by another instance of one or more digits followed by a period followed by one or more digits.