Classes and Objects - The Java Programming Language - page 89

System.out.println("Body " + sun);
System.out.println("Body " + earth);
The toString methods of sun and earth are invoked implicitly and produce
the following output:
Body 0 (Sol)
Body 1 (Earth) orbits 0 (Sol)
All objects have a toString method whether their class explicitly defines
one or notthis is because all classes extend the class Object and it
defines the toString method. Class extension and the Object class are
discussed in Chapter 3 .
Exercise 2.10 : Add a toString method to Vehicle .
Exercise 2.11 : Add a toString method to LinkedList .
2.6.3. Methods with Variable Numbers of Arguments
The last parameter in a method (or constructor) parameter list can be
declared as a sequence of a given type. To indicate that a parameter is a
sequence you write an ellipse ( ... ) after the parameter type, but before
its name. For example, in
public static void print(String... messages) {
// ...
}
the parameter messages is declared to be a sequence of String objects.
Sequence parameters allow a method to be invoked with a variable
number of arguments (including zero) that form the sequence. Such