StringBuilder vs string constructor - the character

Question

I just saw a code like

        StringBuilder result = new StringBuilder();
        for (int i = 0; i < n; i++)
        {
            result.Append("?");
        }
        return result.ToString();

I know that concatenating with StringBuilder is considered faster (and does not create new instance of a string on every append). But is there any reason we would not prefer to write

return new string('?', n) 

instead?

Answer 1

But is there any reason we would not prefer to write return new string("?", n) instead

The only reason I can think of is unfamiliarity of the developer with the existence of this string constructor. But for people familiar with it, no, there is no reason to not use it.

Also you probably meant:

return new string('?', n) 

Answer 2

The main reason not to use new string("?", n) is that no such constructor exists and it won't compile. However, there is absolutely no reason not to use new string('?', n), and I fully encourage you to do so.