programming-for-dummies

Chapter 1: How Programs Work
In This Chapter
Using keywords
Arranging a Program
Dividing programs into subprograms and objects
Building a user interface
Programming is nothing more than problem-solving. Every program is
designed to solve a specific problem, such as taking the trouble out of
editing text (a word processor), calculating rows and columns of numbers
(spreadsheets), or searching and sorting information (a database).
Before you write any program, you must first know what problem you want
the computer to solve. Computers are best at solving repetitive tasks, such
as calculating rows and columns of numbers in a spreadsheet. Anyone can
do similar calculations by hand, but computers make the task much faster
and accurate.
After you know what problem to solve, the next step is figuring out how to
solve that problem. Many problems may have multiple solutions. For example,
how can someone get from the airport to your house? One way might be
to take the highway, which may be the simplest route although not necessarily
the fastest. Another way may take you through winding roads that can
be harder to navigate.
In general, every problem has multiple solutions with each solution having
its pros and cons. Should you tell someone to take the shortest way to your
house (which might be harder to follow) or the easiest way to your house
(which might take longer to get there)?
Computer programs face this same dilemma in choosing the “best” solution.
One solution might be slow, but require less memory to run. Another solution
might be fast, but require gobs of memory. When deciding on a solution,
you always have to consider additional factors, such as what type of computer
the program runs on, what type of environment the program is used
in, and what type of people are using it.
After you choose a solution, the next step involves dissecting how your
chosen solution works so that you can translate those steps into instructions
for the computer to follow.