Regular Expressions 101

^start of line

Negative Lookahead(?!.*<amb(?:(?!<\/amb).)+<amb)

.*any character (except for line terminators), repeated any number of times

<ambthe literal text <amb (case sensitive)

Non-Capturing Group(?:(?!<\/amb).)+

+repeats the group contents below at least once:

Negative Lookahead(?!<\/amb)

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

ambthe literal text amb (case sensitive)

.any character (except for line terminators)

<ambthe literal text <amb (case sensitive)

.+any character (except for line terminators), repeated at least once

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?!.*<amb(?:(?!<\/amb).)+<amb).+$

New

anything <amb id="1">word1</amb> anything <amb id="2">word2</amb> anything // Ok

anything <amb id="1">anything<amb id="2">word2</amb>anything</amb> // KO

anything <amb id="1">word1</amb> sss anything <amb id="1">word1</amb> ddd anything <amb id="1">word1</amb> ddd anything <amb id="1">word1 anything <amb id="1">word1</amb> sss </amb>