Regex to find two strings within a pipe delimited string

Question

I need to find a match within the delimited string if the following two words appear between the pipes: apple and red

Example string 1 (should give a match):

|big blueberries blue|awesome lemon yellow|apple nice delicious red|

Example string 2 (should not give match):

|big blueberries apple|awesome lemon yellow|nice delicious red|

RegEx tried:

^.*?apple.*?red.*?

Which (kind of) works, but not sure how to include the pipe logic i.e. search between pipes.

The fourth bird · Accepted Answer · 2022-03-03T12:22:14.997

1

If the 2 words in that order have to be between 2 pipes:

^[^|\r\n]*\|.*?\bapple\b[^|\r\n]*\bred\b[^|\r\n]*\|.*

^ Start of string
[^|\r\n]*\| Match any char except | or a newline and then match |
.*? Match as least as possible
\bapple\b Match the word apple
[^|\r\n]* Match optional chars other than | or a newline
\bred\b Match the word red
[^|\r\n]*\| Match any char except | or a newline and then match |
.* Match the rest of the line

.NET Regex demo

If the order does not matter, you could use a capture group for either apple or red, and match the same word again, asserting that is using a negative lookhead and a backreference that it is not already matched:

^[^|\r\n]*\|.*?\b(apple|red)\b[^|\r\n]*\b(?!\1)(?:apple|red)\b[^|\r\n]*\|.*

See another .NET regex demo

edited Mar 03 '22 at 12:22

answered Mar 03 '22 at 12:11

The fourth bird

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Could you please give an example if order does not matter (between the 2 pipes). Thank you! – apples-oranges Mar 03 '22 at 12:12
1

@apples-oranges If the order does not matter, you could for example use `^[^|\n]*\|.*?\b(apple|red)\b[^|\n]*\b(?!\1)(?:apple|red)\b[^|\n]*\|.*` https://regex101.com/r/7UeNnW/1 – The fourth bird Mar 03 '22 at 12:17
Sorry for the late reply -- what if I want to match only one word in between the pipes. I assume this will work?: `^[^|\r\n]*\|.*?\bapple\b[^|\r\n]*` Thanks again! – apples-oranges Mar 07 '22 at 13:39
1

@apples-oranges That is correct, if you want to be sure that there is an ending pipe you can also extend it to `^[^|\r\n]*\|.*?\bapple\b[^|\r\n]*\|` – The fourth bird Mar 07 '22 at 14:15

score 0 · Answer 2 · answered Mar 03 '22 at 12:08

If "apple" and "red" need to appear between the pipes, use:

^.*?apple[^|]*red.*?

Explanation: Force any characters between "apple" and "red" not to be a pipe symbol |. You can also get rid of the greedy match ?, then.

See for yourself at regex101...

Regex to find two strings within a pipe delimited string

2 Answers2