正则表达式比较字符串中的数字

Question

I have strings like:

1.2.3
1.4.0.136
V312
V10
2.2.2
r1elease2.0.0
Vr 1.5.1

I want to get regex that should extract versions (without string) out of these strings and arrange in sorter order. Any two strings can be passed at a time to compare.

1.2.3 should become 1.2.3 (no change)
1.4.0.136 should become 1.4.0.136 (no change)
V312 should become 312 
V10 should become 10
2.2.2 should become 2.2.2 (no change)
r1elease2.0.0 should become 2.0.0
Vr 1.5.1 should become 1.5.1

I tried /[^0-9\\.]+/g but it didn't worked in case r1elease2.0.0 as this string became 12.0.0 which is incorrect.

Answer 1

For you example data, you could use:

\\d+(?:\\.\\d+)*\\b

This will match one or more digits followed by a zero or more times repeated pattern of a dot and one or more digits. It ends with a word boundary \\b so the 1 in r1elease2.0.0 does not match.

Explanation

• \\d+ One or more digits
• (?: Non capturing group
  • \\.\\d+ Match a dot and one or more digits
• )* Close non capturing group and repeat zero or more times
• \\b Word boundary

Answer 2

Try:

(?<=^|[\w\s])\d+(?:\.?\d+)*$

Demo

Answer 3

You can do:

(\\w\\s?)*?(\\d+(?:\\.\\d+)*\\b)

and perform the replacement with captured group 2. The part with \\d+(?:\\.\\d+)*\\b was explained by The fourth birth. The part (\\w\\s?)*? gets discarded in the replacement. Output:

1.2.3
1.4.0.136
312
10
2.2.2
2.0
1.5.1