- Get Ready to Program
- What a Computer Program Does
- Common Programming Misconceptions
- Many Programs Already Exist
- Programmers Are in Demand
- The Real Value of Programs
- Users Generally Don't Own Programs
- Giving Computers Programs
- Your First Program
- Clarifying Comments
- Entering Your Own Program
Common Programming Misconceptions
This text aims directly at the heart of the matter: Computers are easy to use and easy to program. A computer is nothing more than a dumb machine that “knows” absolutely nothing. You must supply the program that tells the computer what to do. A computer is like a robot that waits on your every command and acts out your instructions exactly as you give them. Sometimes your program instructions are incorrect. If they are, the computer goes right ahead and attempts them anyway.
Many misconceptions about computers exist and stem from a lack of understanding about how computers work and what computers are physically capable of doing. This book wants to shoot down the myths and improve your understanding of these machines. You’ll be programming computers in no time. The computer is nothing more than a tool that helps you do certain types of work. The computer itself is not bad or good. A hammer is a tool you can use for good (to build houses) or for bad (to break things). A computer in the wrong hands can be used for bad purposes, but that isn’t the computer’s fault any more than it is the hammer’s fault if someone misuses it.
The next three sections attack the three most popular computer myths. Have you heard any of them? Did you think some were true?
Myth 1: Only Math Experts Can Program Computers
Thank goodness this is a myth and not reality—thousands of people would be out of work (including most computer book authors!). Computers would be elitist machines used by only the best engineers and scientists; the casual user could not master them. Computers would still be beneficial in some areas but they would not provide the benefits that so many people can enjoy.
Not only can you be poor at math—you don’t even have to like math or have the desire to learn math to be a good computer programmer. The computer does all the math for you; that’s one of its jobs. There are countless expert computer programmers in the world who cannot tell you the area of a circle or the square root of 64. Relax if you thought this myth was reality.
Programming can provide beneficial side effects. It turns out that, as you become a better programmer, you may find your math skills improving. Developing programming skills tends to improve your overall capability for logical thinking, which underlies many skills in math as well. Therefore, being better in math might be a result of programming but it’s not a prerequisite.
Myth 2: Computers Make Mistakes
You might have heard the adage, “To err is human, but to really foul things up takes a computer!” This might be accurate, but only in that a computer is so very fast that it duplicates a person’s mistakes rapidly.
Computers do not make mistakes—people make mistakes. If you have heard a bank teller tell you that $24 was incorrectly deleted from your savings account because “the computer program made an error,” the teller probably has no idea what really happened. People program computers, people run them, and people enter the data that the computer processes.
The odds of a computer randomly fouling up a customer’s bank balance are minute. Computers simply do not make random mistakes unless they are programmed incorrectly. Computers are finite machines; when given the same input, they always produce the same output. That is, computers always do the same things under the same conditions. Your job, as you learn to program, will be to reduce the chance of computer mistakes.
When a computer malfunctions, it does not make a simple mistake; rather, it really messes things up. When a computer fails, it typically breaks down completely, or a storage device breaks down, or the power goes out. Whatever happens, computers go all out when they have a problem and it is usually very obvious when they have a problem. The good news is that computers rarely have problems.
Before people invented computers, banks kept all their records on ledger cards. When a teller found a mistake (possibly one that the teller had made), do you think the teller said, “The ledger card made a mistake”? Absolutely not. Computers can have mechanical problems, but the likelihood of small mistakes, such as an incorrect balance once in a while, is just too small to consider. Such mistakes are made by the people entering the data or by (gulp) the programmers.
Myth 3: Computers Are Difficult to Program
Computers are getting easier to use, and to program, every day. If you used a microwave, drove a car, or used an iPod recently, then chances are good that you used a computer when you did. Yet, did you know you were using a computer? Probably not. The makers of computers have found ways to integrate computers into your everyday life to monitor and correct problems that might otherwise occur without them.
Of course, if you are reading this book, you want to learn enough about computers to write your own programs. Writing computer programs does take more work than using a microwave oven’s computerized timer functions. The work, however, primarily involves getting down to the computer’s level and learning what it expects.
Not only are computers getting easier to program every day, but you have more opportunities to learn about them than ever before. Cable television channels are loaded with educational shows about using and programming computers. Books and videos on the subject are all around you. The Internet itself contains scores of classes on all aspects of computers and other topics. There is probably a computer programming class now in session somewhere within 15 minutes of your house as you read this.