What is the regex for a string that has no pipe (|) character?

Question

What is the regular expression for a string that should not contain a pipe (|) character? e.g., "this is an example |" of a string with a pipe character.

`[^|]*` <-- Something like this? What's the language? – nhahtdh Jul 23 '12 at 09:17 — nhahtdh, Jul 23 '12 at 09:17
@Jithin: You are rejecting empty string, which is valid. – nhahtdh Jul 23 '12 at 09:19 — nhahtdh, Jul 23 '12 at 09:19
@nhahtdh Yeah, thanks for notifying.. – Jithin Jul 23 '12 at 09:25 — Jithin, Jul 23 '12 at 09:25

score 5 · Answer 1 · answered Jul 23 '12 at 09:17

5

Use a negated character class:

\A[^|]*\z

Explanation:

\A    # Start of string
[^|]* # Match zero or more characters except |
\z    # End of string

answered Jul 23 '12 at 09:17

Tim Pietzcker

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score 2 · Answer 2 · edited May 23 '17 at 11:43

2

Normally, you don't need a regex to find out if a character is included in a string or not.

You didn't specify a language; e.g. in Perl, you could use the tr operator:

if( $string !~ tr/|// ) {
   ...

or you could just look up the character and check its index (-1 if not there):

if( index($string, '|') == -1 )
   ...

Other languages surely have comparable language constructs (VB.NET, Java, SQL, Matlab, C++ etc.).

edited May 23 '17 at 11:43

Community

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answered Jul 23 '12 at 09:24

rubber boots

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yeah, regexes are evil for this task. – gaussblurinc Jul 23 '12 at 10:00

score 0 · Answer 3 · answered Jul 23 '12 at 09:19

0

If what you wanted to ask is: what is a regex to match a line that haven't got the pipe symbol then: the answer is: ^[^|]*$

That is match an entire line of zero or more characters that are not |

answered Jul 23 '12 at 09:19

Chen Levy

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What is the regex for a string that has no pipe (|) character?

3 Answers3