title: Java - Calling functions in extended classes through an object array
body: <p>I've got an array of objects, some of which use an extended version which contains a function not available in the base class. How can I call that function through the array when the array is defined by the base class?</p>
  
  <p>Example</p>
  
  <pre><code>Shape[] shapes = new Shape[10];
  
  shapes[0] = new Circle(10) //10 == radius, only exists in circle class which extends Shape
  
  shapes[0].getRadius(); //Gives me a compilation error as getRadius() doesn't exist in the      
  Shape class, only in the extended Circle class. Is there a way around this?
  </code></pre>