I like it... what keeps the while-body statement from capitalizing the whole -_ delimitted word, and not just the first character? I would think it would return eye_AM_A_HERO instead of eye_Am_A_Hero. No?

\w is a word character
\W is a non-word character

Why so?

it looks nice, though its much better to NOT use regular expressions.

I don't understand the regex, what's the meaning of "(\w)" ?

How does it works ? Can someone write me precise explanation ?

thx, i got it, already.

Ternary expression to check whether the string is longer than 1 char in length, if it's shorter the .substring method will fail so instead just return str. It's good practice to handle edge cases.

Awesome ^^

could u plz explain, using ?true:false; ?

This code fails with "--" as an input. I expected an empty string but had back "--".

This solution gives an incorrect result. "NOT-camMel-case" will be converted to "NOTCamMelCase".

Oh! I thought you meant that the StringBuilder class is not available before Java SE 9 ^^'
All good, thanks for explanation <3