I need to make a regular expression that matches something like:
JG2144-141/hello
or
!
but not:
laptop bag
or a string consisting of whitespace chars only (' ').
Right now I have [A-Za-z0-9-!/\S], but it isn't working because it still matches with laptop and bag individually. It shouldn't match laptop bag and the empty string at all.
The \S in [A-Za-z0-9-!/\S] makes this character class equal to \S, but you want to make sure all chars in the string are non-whitespace chars. That is why you should wrap the pattern with ^ and $ anchors and add a + quantifier after \S to match 1 or more occurrences of this subpattern.
You may use
^\S+$
See the regex demo
Details
^ - start of string\S+ - 1 or more non-whitespace chars$ - end of string.
