Fastest way to put contents of Set to a single String with words separated by a whitespace?

Question

I have a few Sets and want to transform each of these into a single String where each element of the original Set is sep

Answer 1

Maybe a shorter solution:

public String test78 (Set set) {
    return set
        .stream()
        .collect(Collectors.joining(" "));
}

or

public String test77 (Set set) {
    return set
        .stream()
        .reduce("", (a,b)->(a + " " + b));
}

but native, definitely faster

public String test76 (Set set) {
    return String.join(" ", set);
}