I need to match "-" or "_" followed by an alphabetic character (A-Z,a-z). So for example, for "simple-hello_world-" i need to match the "-h" and the "_w".

This is my regex: /-|_[A-Z]/i

But it appears that the [A-Z] is an optional match because it matchs if the string ends with a "-" or with a "_":

"hellogworld-".match(/-|_[A-Z]/i)

[ '-', undefined, index: 11, input: 'hellogworld-', groups: undefined ]

Any help is appreciated.