JavaScript : Object-Oriented Programming

Exercises

1. Create an object called shape that has the type property and a getType() method.
2. Define a Triangle() constructor function whose prototype is shape. Objects created with Triangle() should have three own properties—a, b, and c, representing the lengths of the sides of a triangle.
3. Add a new method to the prototype called getPerimeter().
4. Test your implementation with the following code:

   > var t = new Triangle(1, 2, 3);
   > t.constructor === Triangle;
          
   true
   > shape.isPrototypeOf(t);
           true
   > t.getPerimeter();
          6
   > t.getType();
          
   "triangle"
   

5. Loop over t showing only own properties and methods (none of the prototype's).
6. Make the following code work:

   > [1, 2, 3, 4, 5, 6, 7, 8, 9].shuffle();
          
   [2, 4, 1, 8, 9, 6, 5, 3, 7]