Chapter 8 SOLID

What is Software Design Document

What is the Software Product

"A design that works, but can’t be maintained. Something that is unstable, and hard to change." is sometimes called

the tendency of a system to be hard to change is called

When small code changes force system rebuilds it indicates

When a small change in one module causes other unrelated modules to misbehave, its called

When a system's internal components cannot be easily extracted and reused in novel new environments, its called

What forms SOLID principles

Thus the sender does not depend upon the recipient. Nor does the recipient depend upon the sender. They both depend upon the message; and the message is an abstraction. The dependency opposes the Flow of control. This is the essence of OO.

The essential quality of OO is the ability to invert key dependencies in order to protect high level policies from low level details. It helps in Dependency Management.

A very simple but confusing puzzle. A lady buys goods worth Rs.200 from a shop. (shopkeeper is selling the goods with zero profit). The lady gives him Rs.1000 note. The shopkeeper gets the change from the next shop and keeps Rs.200 for himself and returns Rs.800 to the lady. Later the shopkeeper of the next shop comes with the Rs.1000 note saying “duplicate” and takes his money back. What is the loss of first shopkeeper?