Regular Expressions 101

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/
<xx>((?!<\/xx>).)*?ZZZ((?!<xx>).)*?<\/xx>
/
<xx>
matches the characters <xx> literally (case sensitive)
1st Capturing Group
((?!<\/xx>).)*?
*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
Negative Lookahead
(?!<\/xx>)
Assert that the Regex below does not match
< matches the character < with index 6010 (3C16 or 748) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
xx>
matches the characters xx> literally (case sensitive)
. matches any character (except for line terminators)
ZZZ
matches the characters ZZZ literally (case sensitive)
2nd Capturing Group
((?!<xx>).)*?
*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
A repeated capturing group will only capture the last iteration. Put a capturing group around the repeated group to capture all iterations or use a non-capturing group instead if you're not interested in the data
Negative Lookahead
(?!<xx>)
Assert that the Regex below does not match
<xx>
matches the characters <xx> literally (case sensitive)
. matches any character (except for line terminators)
< matches the character < with index 6010 (3C16 or 748) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
xx>
matches the characters xx> literally (case sensitive)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/

Test String

Substitution

Processing...