Design is about structure, about the relation of parts to the whole. Programs consist of the following parts or components:
(i) elementary components
(ii) composite components
There are three types of composite components--components having one or more parts:
a sequence is a composite component that has two or more parts occurring once each, in order.
(b) selection
A selection is a composite component that consists of two or more parts, only one of which is selected, once.
(iv) iteration
An iteration is a composite component that consists of one part that repeats zero or more times.
