Examples can be divided into two categories: actual objects with similar sub-components, such as keyboards, grills, buildings, and trees, and common collections of similar objects, such as forests, cities, mountains, or herds.
For example, perhaps we would like the petals in our flower in the above example to be colors other than red. We can provide a parameter, "petal-color" to determine the color of the petals.
(define (flower petal-color) (separator ... (color petal-color) ... ) )With a slight modification of the "flowers" code, we can now create a flower garden with a variety of colors.
The robot arm mentioned in hierarchies was also parameterized.
Some other iterative examples: (courtesy of Beth Blostein and Terry Monnett)