How to write the regular season?

you need to write a regular competition for the field validation that would prohibit the entry of phrases like:
helloworld
heloworld
hello world
helo world
hello-world
helo world
hello_world
helo_world

Tried to do so, but then it only works in chrome:
/(?<=helo|hello|helo |hello |helo|hello|helo_|hello_)world/
March 23rd 20 at 18:52
1 answer
March 23rd 20 at 18:54
Solution
A tremendous thank you) - morris97 commented on March 23rd 20 at 18:57

Find more questions by tags Regular expressions