How to get only numbers from string with XPath

Question

I have a string which contains numbers. Is it feasible only with XPath that I get only numbers from it?

For example: myString="abcd12ef34gh567", result: 1234567

score 17 · Accepted Answer · answered Sep 07 '11 at 17:35

17

Use:

translate(., translate(.,'0123456789',''), '')

This is the so called "double-translate" method, first proposed by @Michael Kay and can be used both in XPath 1.0 and in XPath 2.0.

Of course, in XPath 2.0 using RegeX will generally be more efficient:

replace('abc123def590xyz', '[^\d]', '')

answered Sep 07 '11 at 17:35

Dimitre Novatchev

1

+1, "double-translate" very skilful solution. Regex improvement: `\D` – Kirill Polishchuk Sep 07 '11 at 17:59

score 2 · Answer 2 · answered Sep 07 '11 at 16:16

2

If you can guarantee that the non-digit characters will be only lower-case letters (like in your example), you could do the following in XPath 1:

translate($myString, 'abcdefghijklmnopqrstuvwxyz', '')

You can add other characters to the alphabet string as necessary.

In XPath 2, you could use a regex:

replace($myString, '[^0-9]', '')

answered Sep 07 '11 at 16:16

James Sulak

@_James_Sulak: It isn't necessary to know in advance the set of non-numeric characters -- see my answer. – Dimitre Novatchev Sep 07 '11 at 17:36

2 Answers2