println

[priyak]

we use System.out.println to display a string.such as " hello world" but we may also pass
an object as the argument of the println method and as a result a diferent message describing the object is printed.

my question is how does it distinguish between the string object i want to print intact and any other object i pass (such as an exception).

[hot_cakes]

PrintStream.println has numerous overloads. One of them takes an Object argument. To turn this argument in to a string String.valueOf(obj) is used.

Have a look at the Java API docs for more information (lookup PrintStream.println -- System.out is a PrintStream object).

Edd

[byteCode]

To allow special printing for a custom object eg. You create a Circle class, say, and u want the radius and coordinates of the center printed out when u do a println on it. then overload the toString method from class Object(auto superclass of all classes) and add a 'return "r = "+radius+"c = (" + x + ", " + y + ")"' to it

Nikhil