Introduction

Introduction

Today, most people don't need to know how a computer works.  Most people can simply turn on a computer or a mobile phone and point at some little graphical object on the display, click a button or swipe a finger or two, and the computer does something.  An example would be to get weather information from the net and display it.  How to interact with a computer program is all the average person needs to know.

    proc-ess / Noun:
    A series of actions or steps taken to achieve an end. 

    pro-ce-dure / Noun:
    A series of actions conducted in a certain order or manner.
   

But, since you are going to learn how to write computer programs, you need to know a little bit about how a computer works.  Your job will be to instruct the computer to do things.  Basically, writing software (computer programs) is describing how to do something.  In its simplest form, it is a lot like writing down the steps it takes to do something - a process, a procedure.  The lists of instructions that you will write are computer programs, and the stuff that these instructions manipulate are different types of objects, e.g., numbers, words, graphics, etc...
So, writing a computer program can be like composing music, like designing a house, like creating lots of stuff.  It has been argued that in its current state it is an art, not engineering. 
An important reason to consider learning about how to program a computer is that the concepts underlying this will be valuable to you, regardless of whether or not you go on to make a career out of it.  One thing that you will learn quickly is that a computer is very dumb but obedient.  It does exactly what you tell it to do, which is not necessarily what you wanted.  Programming will help you learn the importance of clarity of expression.

        A deep understanding of programming, in particular the
        notions of successive decomposition as a mode of analysis
        and debugging of trial solutions, results in significant
        educational benefits in many domains of discourse,
        including those unrelated to computers and information
        technology per se.
                                 (Seymour Papert, in "Mindstorms")
   

        It has often been said that a person does not really
        understand something until he teaches it to someone else.
        Actually a person does not really understand something
        until after teaching it to a computer, i.e., express it
        as an algorithm."

            (Donald Knuth, in "American Mathematical Monthly," 81)
   

        Computers have proven immensely effective as aids to clear
        thinking.  Muddled and half-baked ideas have sometimes
        survived for centuries because luminaries have deluded
        themselves as much as their followers or because lesser
        lights, fearing ridicule, couldn't summon up the nerve to
        admit that they didn't know what the Master was talking
        about. A test as near foolproof as one could get of whether
        you understand something as well as you think is to express
        it as a computer program and then see if the program does
        what it is supposed to. Computers are not sycophants and
        won't make enthusiastic noises to ensure their promotion
        or camouflage what they don't know.  What you get is what
        you said.
                                (James P. Hogan in "Mind Matters")
   

But, most of all, it can be lots of fun!  An associate once said to me "I can't believe I'm paid so well for something I love to do."
Just what do instructions a computer understands look like?  And, what kinds of objects do the instructions manipulate?  By the end of this lesson you will be able to answer these questions.  But first let's try to write a program in the English language.