regex101: PCRE (Legacy) Substitution Workspace

1st Alternative(?(DEFINE)(?<skip><ol>.*?<\/ol>))(?&skip)(*SKIP)(*FAIL)

Definition Group(?(DEFINE)(?<skip><ol>.*?<\/ol>))

Group skip(?<skip><ol>.*?<\/ol>)

<ol>the literal text <ol> (case sensitive)

.*?any character, repeated any number of times

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

ol>the literal text ol> (case sensitive)

(?&skip)calls group skip as a subroutine

(*SKIP)acts like (*PRUNE), but the next unanchored match attempt starts where (*SKIP) was reached instead of at the next subject character

(*FAIL)forces the current match attempt to fail at this position

2nd Alternative\s*<li\s+class="myclass">(.*?)<\/li>\s*

\s*any whitespace character, repeated any number of times

<lithe literal text <li (case sensitive)

\s+any whitespace character, repeated at least once

class="myclass">the literal text class="myclass"> (case sensitive)

Group 2(.*?)

.*?any character, repeated any number of times

<the literal < (60₁₀ / 74₈ / 3C₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

li>the literal text li> (case sensitive)

\s*any whitespace character, repeated any number of times

Global pattern flags

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

s modifier: single line. Allows a dot to match line terminators

Search reference

Regular Expression

(?(DEFINE)(?<skip><ol>.*?<\/ol>))(?&skip)(*SKIP)(*FAIL)|\s*<li\s+class="myclass">(.*?)<\/li>\s*

New

<ul>
    <li class="myclass">blablabla 1</li>
    <li class="myclass">blablabla 2</li>
    <li class="myclass">blablabla 3</li>
</ul>
<ol>
    <li class="myclass">blablabla 1</li>
    <li class="myclass">blablabla 2</li>
    <li class="myclass">blablabla 3</li>
</ol>
<ul>
    <li class="myclass">blablabla 1</li>
    <li class="myclass">blablabla 2</li>
    <li class="myclass">blablabla 3</li>
</ul>

Substitution

<div class="newClass">$3</div>\n