Java String.valueOf(null) throws NPE, but Object a = null; String.valueOf(a) returns 'null' [duplicate]

Answer 1

The first invocation is to String#valueOf(Object), the second is to String#valueOf(char[])

The overloaded method is chosen according to the argument's static type, this is why the first works and the seconds get an NPE.

If you invoke System.out.println ( String.valueOf((Object)null)); it will work