Book 1 Chapter 1
1. Introduction1.1 I'm looking for Programming Class for Beginner
The students of FISHOIL High school were in their classroom. It has been five minutes after the bell rang. There was no teacher. 10 minutes past, somebody was walking rather rapidly in the hallway. Then he opened the door and stuck his head in."Is this the classroom for beginning computer programming?" He asked.
"Yes, it is."
"Good, I'm in the right place, then." He smiled.
He walked toward to the blackboard. "I have bad news and good news. The bad news is that your old teacher cannot make it. He had an accident involving his back. So, he's in the hospital for now, and will be for the foreseaable future." The students were surprised.
"Don't worry, it's alright. It's not life threatening or anything like that." He smiled. "Well, now the good news: I'll be substituting for him until he gets well. My name is Ramstrong, but you can call me Teacher. I'll be teaching you all the knowledge of computer programming from the ground up until you are competent. Or at least not clueless like you are now. Gya ha ha ha." Bad joke already. The students feel a sudden chill. "Anyway, ready to start?"
There was nothing the students could do. All the classes have been scheduled, and all the students could do is to just sit there and follow through. The new substitute teacher seemed well enough, but really, the only way the students could petition for another teacher is if this one was so terrible, the only other choice is to cancel the class.
“So, you have a choice to make,” he said with glistening eyes. “Do you want to work hard and maximize your learning potential, or do you want to just take it easy and cruise, and get good grades on easy subject?” That was unexpected. Teachers don't usually make that kind of offer. The students were mulling on the idea.
A total confusion reign among the students. Is this teacher for real? Does he just want to teach the barest knowledge good enough to pass the test? Of course, teaching to test is a reasonable choice if you want a good grade. Everybody knows that computer programming is hard enough. If there's any advanced knowledge required to pass the test, then there's a good possibility that the student will fail the class.
On the other hand, not learning good knowledge in the beginning may jeopardize the future of learning. Remedial classes come to mind. What if learning just the core knowledge proved insufficient? What will the future course will hold? This is a very important decision to make for the students.
“So,” the teacher said impatiently, “Does anybody here just want to take it easy?”
“Yes!” said somebody in the back. His laid back posture and unbuttoned shirt shows his deliquent nature. “I like to just take it easy. Just cruise along, do nothing, and get good grades, you know?” He smiled confidently at the offer. “This is going to be an enjoyable class”, he thought.
The teacher didn't say anything. He merely yanked the student off his feet and took him outside. When they came back, the student looked like he was drowned, wet, pale and scared.
“Anybody else?” The teacher asked.
“WE'LL STUDY!!!” all the rest of the students shouted in unison. Not agreeing to do so can be deadly!
1.2 Why do you want to learn how to program? Old guy
The bell rang and the old teacher entered the classroom soon after. The old gentleman is in his 70s and it is obvious that he is passionate about the subject. The students are all eager to participate in the learning."Now, then," the teacher asked. "Before we begin, we should be learning about each other." His gentle manner is very reassuring. The students were happy to have him as the teacher. He came highly recommended by everybody. "So, how about you tell me the reason why you want to learn computer programming?"
"I want to learn how to write Minecraft" somebody said.
"Doom", said another.
"How about Call of Duty, or Battlefield"
The teacher beamed. "Well, well" he said, "These are all excellent reasons to learn computer programming. You can get ahead in the computer industry programming these games. I would be lying if I say that these are easy to do. You need years of computer programming experience to be able to program those programs, but I'm sure with perserverance, you'll be able to do it."
"Is it really that hard to program?"
"Do we need to be good at math?"
The teacher beamed some more. "Very enthusiastic students! I'm sure we'll do well. This class is what is known as beginning computer programming. It will build the foundation of which every computer program is built. Trust me that you will need to learn much in order to succeed. I hope you understand that some of the things you need to learn involves Math. You need a high degree of mathematic in order to be successful in computer programming." The teacher nodded his head sagely.
"All the problems being solve by computer involves math in some capacity, so it is important that you know your math skills very, very well." Some students become nervous. "Don't worry. I will teach you all the math you need in order to succeed in being computer programmer.
"Now let's talk a little bit about the evolution of computer programming, and we'll explore various computer programming languages that is optimised for maximum learning."
A student raised his hand, "You mean there's more than one programming language?"
The teacher smiled. "Yes, there are many. Don't worry, you don't need to learn them all. We're going to focus on the languages for learning."
"You mean BASIC." Said a student
"No, no BASIC." The old teacher looked rather disappointed. "Do you know that BASIC programming language actually caused brain damage?" The students are surprised. "It's true. A professor actually wrote a paper saying so. You're not going to argue with a professor, will you?" Of course, no student will.
"Well, let's go over the different languages available. You are lucky that you have so many computer languages to choose from. You mentioned BASIC, so let's talk about that for now."
BASIC stands for Beginner All-purpose Symbolic Instruction Code. Despite the name, it is a very poor language for beginners indeed. For one thing, GOTO causes programs to be so convoluted, that it resembles spaghetti." The student laughed nervously. "It's true. Spaghetti code is the ban of BASIC computer programmers.
"Furthermore, there is no structure involved at all. It makes it hard to read when everything is lined up to a straight line. Once you learn structured programming, you won't ever want to go back because the the only way to manage complexity is by structuring your program well, and you can't do it with BASIC. Not to mention that old BASIC interpreter is so slow, it's a miracle to get anything done.
"Now, the problems of Basic are so well known that several very smart people have come up with a solution. One of the better one is Pascal. Pascal is named after 17th century physicist. It's a very logical language and very structured. All the variables are typed. By that I mean that numbers and letters are different." He surveyed the class. A few students look confused.
"Consider the fact that computers are basically binary, ones and zeroes. Obviously, this causes confusion. By limiting and enforcing different data types, the program does not allow the programmer to just randomly enter code into the computer. No experiment is allowed!" A few students giggled nervously. "This obviously goes to a great distance in structuring your program. For the first time in the history of computer programming, you need to plan your computer programs, instead of just randomly type code in and hope that it will work.
"Let me emphasize this clearly: Hope is not a good ingredient in writing computer programming!" The teacher nodded his head sagely, as knowing from experience the folly of such activity. He was bringing years of experience into the classroom. The freshman students of FIShOil High school feel blessed.
"What about C computer language?" Asked a student.
"Ah, C computer language." The teacher nodded his head sagely, "It is a very popular language. In fact it influenced many other computer languages available today. Do you know that C++, C#, and even Java was influenced by C language? You have to admit that despite many shortcomings, C is indeed a very popular language! Do you know why C language is popular?"
"Because it's powerful?"
"Yes, absolutely correct. Indeed, it is very powerful. That's why professionals are using it." The old teacher looked at the students warningly. He was about to warn the students from erring to the bad path. "And yet, it is a very troublesome language, indeed."
"That's why people kept improving the language." As he looked over the classroom, every eyes was fixed to his, breathlessly waiting for what's next. "First, C++ added Object oriented capability, and yet, it is not enough! Then Java removed the most dangerous elements: Pointers. You can no longer use pointers in Java. In addition, Java programming language provides a Godsend of a feature: Automatic Garbage Collection. No longer are computer programmers beholded to managing their memory, those mundane activities are done automatically by the computer, as it should be. This frees up the person to concentrate on computer programming problems, instead of fighting the language just to get things done."
"So, we're going to use Java?"
"No, we won't," the old teacher smiled patiently. "We'll be using Python programming language. Does anybody ever heard of it?"
"I know of Perl", volunteered somebody
"Ah, Perl. I suggest that you stay away from it also. Unfortunately, all the follies of BASIC is present in Perl. Do you know that the language is so difficult to read, that it is often faster to write the program from scratch than reading the source code?" All the students just shaked their head. They simply didn't know. It's a good thing they have the old wise teacher to guide them through this.
"Python is very readable, strongly typed, object-oriented, and very, very powerful. And yet, it is simple to use. Even beginners have been able to create powerful programs with it, thanks to comprehensive libraries available. So, that is what we will be using.
"No pointers, no memory allocation, and definitely no GOTO!" The last word, the old teacher said sternly. It is very important that the students are guided well, so that they will prosper in the future.
"And now, let's take class roll." He picked up his rollbook and started calling students name one by one.
1.3 Why do you want to learn how to program? New guy
"So, as I understand it, you guys just started yesterday." The new substitute teacher does not look like a teacher at all. He looks more like some dumpy guy. A fashion challenged geek. "May as well start fresh. Losing a day isn't going to be that big of a deal."So, why do you want to learn computer programming?" He asked.
"I want to write Minecraft!" said a student. “Doom" said another. "CALL OF Duty" said another one.
"Gyah ha ha ha! Are you guys serious?!" He was laughing his head off. "THAT is why you want to learn computer programming? What a bunch of morons!" The students are shocked!
"If that's all you want to do, you definitely do NOT want to learn computer programming. Are you kidding me?" He was just off into his own world.
"Just use their level editor and be done with it! You do know that those games comes with their own level editors, don't you? Why do you want to bother learning computer programming for?" He was so obviously disappointed with the students.
"But the old teacher said those are good goals!" The student protested.
"Ha! That's because he's a teacher, and he can't say anything else to you. Too bad I'm not a teacher!" The students were confused. "I am what is known as Experienced Professional." He explained. "I'm a working professional and don't care what this mumbo-jumbo educational institution is teaching you. I'm only concerned with what works, and what's out there!"
"So you don't make games?"
"Of course, I do! It's just that if you asked professional computer programmers out there, they don't really make games. They make those level editors! The ones using the level editors are artists and designers. That's because artists and designers are hopeless when it comes to math necessary to build those modellers and level editors. On the other hand, software engineers cannot tell the difference between good design and total turkey! Therefore, by letting computer programmers build the tools, and artists and designers build the games, everyone benefits. Now you are telling me that you want to make games? Well, I suggest that you learn art and design, because if you're learning computer programming, then you'll never get there!"
The students were absolutely speechless! They never expected such harsh words coming from their teacher, although to be fair, he's not their teacher. He's just somebody substituting their teacher until he recovered well enough to resume teaching.
"Any question so far?"
"Well, then why do we want to learn computer programming?" Asked a student.
"What? You mean this is not a required class?" He looked shocked and disappointed. "Are you kidding me? Everyone should learn how to program!"
He was watching the class like a hungry hawk. It's obvious that he's looking for blood. "Are you telling me that you are so completely clueless about why you should learn this?"
"But if not for games..."
"You want to learn computer programming because you are lazy, and you don't want to work hard. Computer programming ... " he paused for effect, "is one of the easiest, if not THE easiest job around. I mean, all you have to do is sit around all day! How can you beat that?" That does make it sounds nice and easy.
"Of course, there's a qualification for that." He smiled. "That's true ONLY if you know what you're doing. Do you know how many people don't know what they're doing?" He asked rhetorically.
"Very little of them?" Answered a student.
He scowled. "90% of people don't know what they're doing!"
"Whaaat? That many?" The students are surprised. "Are you sure?"
"Judging from my college days, in the class of 50 students, the ones I consider know what they're doing are about 2 or 3. " He said glumly. "Another 2 or 3 SOMEWHAT knows what they're doing. The rest don't have a clue.
"Extrapolate that to 100% and a full 90% of students don't know what they're doing. Sad but true."
The students were shocked into their seats. They simply don't know what to expect.
"Anyway," The guy broke their silence, "I figure that we'll start you with the basics and make your teacher proud in having you as students. So, you're up on your text books?"
"Umm, yeah, we're learning Python."
"Whaaat? Python as first learning computer programming language?! Whose stupid idea was that?"
"The old teacher said it's a good language."
"Pshaw! What does he know about Python. Perl would be better!"
"But Perl is a read only language!"
"Oh yeah? Says who?"
"The old teacher said that it's faster to rewrite the program from scratch than it is trying to read it."
"Well, that's true in some circumstances, but that's not the fault of the language. It's the fault of the programmer. If the programmer decides to use the full language, magic variables and all that, then certainly it can be hard to read. The thing is, you're supposed to know the language well, and if not, have the decency to ask. If you don't bother learning the language, then of course, you can't read the code. That's true with just about any language including Python. Get real!
“Plus, Perl is so fast and easy to write, it's no wonder you can write it faster than to read it. I mean, imagine the ease of programming. You can, more often than not, write the program as you are explaining the steps to the computer. It can be written as fast as you speak! What other computer languages can make that statement? None that I can think of!
“This is because Python, being designed by a mathematician, has all the trappings of 'formalities', this rule, and that rule. Where as Perl, being designed by a linguist, means that it's very fluid and easy to write.
“The problem is that most people don't know what they're doing, remember? So, most people are having trouble explaining the steps, and of course, they'll be having trouble reading the mumbo-jumbo they've been putting into the computer!”
The students are simply shocked into silence. It's like everything that the old teacher said was wrong. What can they possibly be learning? “Is this true?” Finally somebody asked.
“In my experience, it's true.” The teacher said. “Of course, I do have several techniques in my arsenal as to avoid confusion. I maintain a programmer's journal, for example.”
“What's a programmer's journal?”
“Well, a programmer's journal is a journal, of course. What should go in there? All your thoughts about the problem, and potential solutions. All your attempts and gotchas. In some cases where the algoritm is quite advanced, I actually wrote a dissertation of the problem and the various ways to solve it. In other words, I'd be teaching the readers on how to solve the problem!
“This is something that most people just don't bother doing. They think that a well-commented source code is enough to be readable. Well, I'm telling you guys right now that IT IS NOT ENOUGH!” He said the later words with great emphasis.
“Program maintainers are usually polled from low-ranking personnel, and they don't have the programming skill anywhere near a professional. How can you expect them to be able to handle sophisticated problem? They can't! And yet so many project managers will just throw these rookies into the most complicated project without so much a guidance. No wonder they failed. What do you expect?”
“Therefore, a programmer's journal is a necessary ingredient in a project, not only will it tell you what to do, but also what not to do. The rookies will be able to grow just as the experienced professional grew when he tackled the project. The difference is, the rookie will grow much faster because all the wrong steps have been mapped out.
“In short, any project manager who doesn't insist on a properly written programmer's journal, and will accept a well-written commented code, perhaps with a little flowchart on the side, is a bad project manager who will doom the project into long development time, high frustration and turn-over rate, and a very, very expensive proposition, indeed.
“Do you know how many project managers are like that?” He asked rhetorically, “Most of them. In fact, I've never heard of any that requires programmer's journal, and only a handful computer programmers, professionals or not, are maintaining such journal.
“And that's why computer programming is so hard! Everybody will have to stumble to the same mistakes all over again. Wouldn't it be better if such mistakes are documented and therefore be avoided in the future?” All the students nodded their head. “Well, it's not being done that way. Too bad. You just have to stumble to the same mistakes just like everybody else!”
The students were confused.
“But, aren't you going to let us know what those mistakes are so that we can avoid them?”
“Nope. Not in the cards!” the teacher just laughed. “Pick any computer textbook available, do you see them putting in warning after warnings? Not on your life!
“You see, everybody makes different kind of mistakes, and it will fill a whole encyclopaedia to list those mistakes. What a waste of time. Why write all the mistakes down when each student will only experience a small fraction of it? Better to let the students fail, and make them learn from their mistakes! That's the fastest way to learn.
He winked, “Of course, there no need for you to go down the wrong path to begin with, so no Python for you! Let's start you guys properly and begin with a good development platform for beginners. Perl is definitely better than Python.”
"But Perl encourages rewriting,” said a student. “Don't you think rewriting from scratch is bad?"
"Of course not. In fact, there's a adage in computer programming: Prepare to throw one away. You will anyhow." The students are all speechless. "I'm surprised your old teacher doesn't know it. I don't suppose he's all that experienced, is he?"
“So, let's just use something that is fun, convenient, and easy to use. I have just the thing for you: Petit Computer. You're going to like it since it is BASIC and runs on Nintendo DSi!”
The students blinked uncomprehendly. “You mean we're not going to use a computer?”
“Whadaya mean 'we're not going to use a computer?' Didn't I just tell you that we're using Petit Computer? That's a computer right there! Are you some kind of stupid?” The teacher glowered.
“Ummm, but Nintendo is for games.”
“Of course, it is. You want to be computer game programmers, don't you? What can be better? Just use one of those computer game machine and be done with it! It's portable, convenient, with plenty of computer game examples around. It's a full computer game development in the palm of your hand!” The teacher scanned the classroom. “I can't believe you're not excited about it at all! There's no better development tools available for what you want to do!”
The students aren't convinced, of course, especially as their old teacher was pointing out just the opposite the day before, but as they feared they will anger the substitute teacher, they kept quite. Finally somebody spoke up, “What about C computer language? It's powerful enough for anything, isn't it? Why can't we make games with that?” Other students feared the worst. Thunderstrike time!
“Oh, C programming language,” the teacher mused. “What makes you think it's powerful?”
“That's what everybody says.”
“Of course, 90% of them don't know what they're talking about.”
“So, it's not true?”
“C programming language is actually not that powerful. Python is a whole lot more powerful than C. In fact, you can say that C programming language is downright primitive! It's very simple. Most people can learn it in about 20 hours. Of course, knowing the language is different than being fluent with it. It took me another 20 hours, for 40 hours total, before I get to be comfortable with it.
“The thing about C is that it's so simple and primitive, you have to do everything yourself. That's why you need to load a bunch of libraries in every C program. And you want to do that because C is what is known as 'portable' language. That means it can run on many different platforms without change. That is very useful to have when computers kept changing every year. But powerful? Not at all.
“People, for all their complicated thinking, are often single-minded about things. In this case, they're mistaking execution speed with power. C program runs very, very fast. However, that's because C program doesn't do anything you don't tell it to do. If you know Java programming language, you know that it does array boundary check automatically, so that if you try to access array outside what is declared, it will throw out an error. No such thing with C.”
“But isn't that desirable? Automatic checking, I mean.” asked a student.
“Of course, not. Automatic anything isn't desirable. Why would you want it?”
“So, we don't have to do it.” came the reply.
“Of course, you have to do it! Why would you not want to do it?”
“But the language does it for us!”
“You mean you want to let somebody else, in this case, the language programmer, do it for you?” He sneered.
“Yes. Wouldn't it be better that way? It'll be better than if we do it, after all.”
“No, of course not. It'll be better if you do it yourself. Think about it. How would he know when to check the array boundary? Well, every time you access the array, either writing to it, or reading from it, right?”
“Uh, yes. That's right.”
“That will slow the program down. You don't want to do it that way.”
“We don't? But what if we write outside the array boundary?”
“What I mean is that you don't want to check for the array boundary EVERY TIME you access the array. What you want to do is do a pre-emptive range checking to see that the range is within the array, THEN you access the array. By that time, you're sure that the access will never go past the boundary, so you don't need to check. Instead of checking the boundary a million times every pass, you just do it once in the beginning. Got it?”
Of course, the explanation went past the students' head. They don't even know what an 'array' is, much less anything about range checking. So, they kept quiet. Not that the teacher missed it. Their dumb looking faces betray all.
He sighed. “Oh, well, we'll get to it later. For now, let's just do a test. Everybody please get a piece of paper out. We'll do a test right now!”
“Whaaat?” The students can't believe it! “But we haven't studied! You haven't taught us anything! How can we do well on the test?”
“What's that? You've never taken a test that you haven't studied for? Gya ha ha! Well, there's a first time for everything! You'll get it eventually, may as well be now! Clear out your desk! We'll start now!”
“Not even a roll call?”
“What for? Your name will be on the paper. I'll learn your names then. If not, you'll get zero. No problem with me.” The teacher then started writing some questions on the board, while the students trembled with fear for the worst.
1.4 Why would you want to learn how to program?
"So, you're here. I didn't know whether or not you'll be here. I mean, you're not a teacher here, so I don't know whether or not you keep the same office hours as the original teacher.” A student was visiting the old teacher's office during “consulting hours.”“Well, I have some work to do, so I may as well do it now, since I don't want to take it home with me.” says Ramstrong the teacher. “This place is just convenient, and it's available for use, so why not use it?”
“Of course. I was just wondering.” the student said.
“And you are? Your name, I mean.”
“I'm Peter Wu.”
“Nice to meet you, Peter. I assume that you have prior computer programming experience?”
“Ah, yes. How do you know?”
“From your questions. Not everybody is interested in computing cycles, you know.”
“Ah, that's true. Well, I do have a question.”
“Yes, what is it?”
“How come we're not using PC? That's what they're using everywhere else. In fact, some of the schools are using C#. Shouldn't we be learning the latest and greatest technology that will be relevant in the industry?”
“Of course, not! You're just a beginner! Besides, it doesn't matter much whether you're learning Basic, C, or C#. Why would you want one over the other?”
“For one thing, C# is as powerful as C++, and it doesn't have pointer.”
“Of course C# has pointer. What are you talking about? How else are you going to pass variables to the function?”
“Huh? C# has pointers? But, but, the book says it doesn't!”
“See what I mean about 90% of people don't know what they're talking about? Gya ha ha ha!”
“So, C# has pointers?”
“See, you want to pass parameters to a function. With C, it's pass by value, so you use pointers. With Pascal, it's pass by reference. C# is just like C, pass by value. So, how do you figure that works? What if you want to pass an array? Or a return value?”
“Well, they use something called 'REF'.”
“Short for REFERENCE, which is a pointer. References are pointers. Simple as that! C# has pointers. It's just that they don't call it pointers. They call it reference!
“C# has pointers?!” Peter couldn't believe it!
“Oh, one more thing. You don't use REF for parameter passing. You use IN and OUT for parameter passing. Which is stupid because it's just like REF, except you don't need to initialize them before using. Otherwise, it's exactly the same! How's that for unnecessary complexity?”
Peter was speechless.
“You'll learn it later as we go, but not all problems need solving. Sometimes, it's best if you can just avoid it in the first place. Take today's exam, for example.”
“You didn't really finish the exam.”
“No, I didn't. There's no point. You guys are so stupid, I'll have to start from the very beginning! Don't expect to be programming very soon.”
“Why not? This is a computer programming class.”
“That's the difference between me and other guys. I insist on teaching you the foundations you need. It'll take a while, but it'll be solid.” Peter can do nothing but agreed to that.
