Question

I need to match & which is present in plain text but it should not capture the & from entities like i

e.g.,

hi this is a plain text containing & and the entity E , ＆ and &

In the above text I should find only & which is in text–i.e., coming after containing.
I tried this pattern &[^#x]* but I couldn’t get all matches.

Answer 1

The stolen regex to match HTML entities from another answer combined with look-aheads:

&(?!(amp|apos|gt|lt|nbsp|quot|bull|hellip|[lr][ds]quo|[mn]dash|permil|
     \#[1-9]\d{1,3}|[A-Za-z][0-9A-Za-z]+);)

Shortened:

&(?!(\#[1-9]\d{1,3}|[A-Za-z][0-9A-Za-z]+);)

Explained:

We want to match & but not &123; etc.

&                 // match an ampersand
(                 // group starts
    ?!            // negative look-ahead (don't match '&' if this group matches)
    (\#[1-9]\d{1,3}|[A-Za-z][0-9A-Za-z]+); // regex to match HTML entity after '&'
)                 // group ends