The ArrayStoreException

• Rectangle[] is a subtype of Shape[]
• Can assign Rectangle[] value to Shape[] variable:

  Rectangle[] r = new Rectangle[10];
  Shape[] s = r;
  

• Both r and s are references to the same array
• That array holds rectangles
• The assignment
  s[0] = new Polygon();
  compiles
• Throws an ArrayStoreException at runtime
• Each array remembers its component type