What does the regex \S mean in JavaScript? [duplicate]

What does /\S/ mean in a regex?

while (cur ! = null) {
    if (cur.nodeType == 3 && ! /\S/. test(cur.nodeValue)) {
        element. removeChild(cur);
    } else if (cur. nodeType == 1) {
        cleanWhitespace(cur);
    }
}

Solution 1:

\s matches whitespace (spaces, tabs and new lines). \S is negated \s.

Solution 2:

\S matches anything but a whitespace, according to this reference.

Solution 3:

I believe it means 'anything but a whitespace character'.