Page History

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• Compile All: the Rectangle file is automatically saved and recompiled.
• To create an instance of class Rectangle, type the following in the Interactions pane:

  Code Block
  Rectangle r = newRectangle(4,5);

  Note: the "Compile All" command resets the Interactions pane erasing all extant
  definitions of names bound to objects. So when we compiled our new definition for the Rectangle class,
  we destroyed our first binding of r in the Interactions pane.
• To "ask" the Rectangle object bound to r2 to compute its area, type

  Code Block
  r2.area();

  in the Interactions pane.
• Experiment with the DrJava Interactions pane to create some new rectangles and computer their areas.

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