The Java Language Specification, Third Edition

TYPES, VALUES, AND VARIABLES Objects 4.3.1
The sample code:
class Point { int[] metrics; }
interface Move { void move(int deltax, int deltay); }
declares a class type Point, an interface type Move, and uses an array type int[]
(an array of int) to declare the field metrics of the class Point.
4.3.1 Objects
An object is a class instance or an array.
The reference values (often just references) are pointers to these objects, and a
special null reference, which refers to no object.
A class instance is explicitly created by a class instance creation expression
(§15.9). An array is explicitly created by an array creation expression (§15.10).
A new class instance is implicitly created when the string concatenation operator
+ (§15.18.1) is used in a non-constant (§15.28) expression, resulting in a new
object of type String (§4.3.3). A new array object is implicitly created when an
array initializer expression (§10.6) is evaluated; this can occur when a class or
interface is initialized (§12.4), when a new instance of a class is created (§15.9),
or when a local variable declaration statement is executed (§14.4). New objects of
the types Boolean, Byte, Short, Character, Integer, Long, Float and Double may
be implicitly created by boxing conversion (§5.1.7).
Many of these cases are illustrated in the following example:
class Point {
int x, y;
Point() { System.out.println("default"); }
Point(int x, int y) { this.x = x; this.y = y; }
// A Point instance is explicitly created at class initialization time:
static Point origin = new Point(0,0);
// A String can be implicitly created by a + operator:
public String toString() {
return "(" + x + "," + y + ")";
}
}
class Test {
public static void main(String[] args) {
// A Point is explicitly created using newInstance:
Point p = null;
try {
p = (Point)Class.forName("Point").newInstance();
} catch (Exception e) {
System.out.println(e);
}
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