As programs get to be millions of lines long, it becomes increasingly important to write code that is easy to understand. If you are working on a million line program, you can never keep the entire pr...As programs get to be millions of lines long, it becomes increasingly important to write code that is easy to understand. If you are working on a million line program, you can never keep the entire program in your mind at the same time. So we need ways to break the program into multiple smaller pieces so to solve a problem, fix a bug, or add a new feature we have less to look at.
