| The classes can provide one or more constructors to initialize a new object of that type. |
| We can recognize a class's constructors because they have the same name as the class and have no return type. |
| Here are the declarations for Rectangle's constructors: |
| public Rectangle(Point p) public Rectangle(int w, int h) public Rectangle(Point p, int w, int h) public Rectangle() |
| If a class has multiple constructors, they all have the same name but a different number of arguments or different typed arguments. |
| The compiler differentiates the constructors, and knows which one to call, depending on the arguments. |
| Using Objects |
| Objects give us two ways to do these things: |
| 1. Manipulate or inspect its variables. |
| 2. Call its methods. |
| Java provides an access control mechanism whereby classes can restrict or allow access to its variables and methods. |
| A class should protect variables against direct manipulation by other objects if those manipulations could endanger the object's state. State changes should then be affected and therefore controlled by method calls. |
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