I'm a bit disappointed such question is on the exam, because throughout the whole scjp-book you learn an int (long, short, float,...) can not be used as a boolean (java is not c or c++) and then suddenly you can convert a float into a boolean This is such a little trifle and a huge important thing (which is used regularly in many different other languages) as regex was not tested at all. I'm curious to know how many people know about this behavior and use it during their development? The ones who really use this, should be <insert really scary thing>
If the argument is null, then the result is "false". If the argument is a boolean or Boolean, then the result is the string returned by String.valueOf(). Otherwise, the result is "true".