Getting a substring of an attribute in XPATH

Question

Given

<foo>
  <bar baz="Hello, World!">
</foo>

How do I all but the last 4 characters of @baz? One of my attempts was:

/foo/bar/@baz[substring( ., 0, -4 )]

Good question, +1. See my answer for the only correct solution so far. :) — Dimitre Novatchev, Dec 01 '10 at 07:38

score 23 · Accepted Answer · answered Dec 01 '10 at 07:38

23

Use:

substring(/foo/bar/@baz, string-length(/foo/bar/@baz)-3)

Do note the 3 in the expression.

The following is wrong:

substring(/foo/bar/@baz, string-length(/foo/bar/@baz)-4)

because this returns the last 5 characters of the string value of the baz attribute.

answered Dec 01 '10 at 07:38

Dimitre Novatchev

@Volkirith, The phrase in the question "How do I all but the last 4 characters" is ambiguous -- maybe it meant "How do I **skip** all but the last 4 characters" in which case the answer is correct. We can't know for sure, but the fact that the answer was accepted kinda confirms this guess. Of course, had it been the other way around (the meaning you suggest in your comment). the solution is easy enough: `substring(/foo/bar/@baz, 1, string-length(/foo/bar/@baz)-3)` Do note that recently moderators and other people have been "correcting" questions -- leading to this mess :( – Dimitre Novatchev Jan 16 '19 at 15:15

score 8 · Answer 2 · edited Dec 10 '12 at 12:18

8

try this: substring-before(/foo/bar/@baz,"rld!")

edited Dec 10 '12 at 12:18

albertjan

answered Dec 10 '12 at 12:02

ecciethetechie

score 4 · Answer 3 · answered Dec 01 '10 at 07:20

4

That's actually not so bad, but IIRC substring doesn't like negative indices. I tried

substring(/foo/bar/@baz, string-length(/foo/bar/@baz)-4)

Which gave me the expected result.

answered Dec 01 '10 at 07:20

Jan Thomä

3 Answers3