How to form regular expression that filters out the words that start with == and end with ==?

Question

I want to filter out all the words that start out with == and also end in == , for example ==Hello== , but I don't want words such as ===Bye=== to be part of such a matching,

I am using the following regex but it doesn't return the results I am looking for: ==(.*?)== , what mistake am I doing in formulating the regex?

Answer 1

==(.*?)== still matches ===Bye=== . You need to check specifically that there is no preceding or following = . You also need to make sure that no = are captured, so .* is not going to work. Use [^=] .

(?<!=)==([^=]*)==(?!=)

http://rubular.com/r/bWpBPf3QXZ

Answer 2

Try this:

([^=]|^)==([^=]+)==([^=]|$)

It handles the match occurring at the beginning or end of the given String as well.

Answer 3

(?<!=)==\K[^=]+(?===)(?!===)

在这里看演示。