Match empty string, comma, hyphen or underscore once using regex

Question

I\'m trying to figure out how to match the following strings:

blaOSXbla
os X bla
bla os-x
blablaOS_Xbla

A common pattern is pretty easy:

Answer 1

Try:

/os[ \-_]?x)/i.test(string)

Use ? to match the previous set zero or one time.

Demo