Javascript regex - no white space at beginning + allow space in the middle

Question

I would like to have a regex which matches the string with NO whitespace(s) at the beginning. But the string containing whitespace(s) in the middle CAN match. So far i have

Answer 1

In your 2nd character class, \\s will match \ and s, and not \s. Thus it doesn't matches a whitespace. You should use just \s there. Also, move the hyphen towards the end, else it will create unintentional range in character class:

^[^-\s][a-zA-Z0-9_\s-]+$