Regex - negative Negative Lookbehind with br

Question

i have a string:

var a = '<<<<<<<br>>>>>>>>'

I want to replace: < with < and > with > , but I don't want to replace <> if it is the <br> tag. So, I'm doing this

a.replace(/<(?!br>)/g, '&lt;').replace(/>(?<!<br)/g, '&gt;')

first replace is working, but the second is not.

Answer 1

Javascript doesn't support lookbehinds so your expression is not valid.

For opening braces:

<(?!\/?\w)

For closing braces:

\B>

\\B denotes a non-word boundary.

JS:

> a.replace(/<(?!\/?\w)/g, '&lt;').replace(/\B>/g, '&gt;')
< "&lt;&lt;&lt;&lt;&lt;&lt;<br>&gt;&gt;&gt;&gt;&gt;&gt;&gt;"