How to program – Some essential tips

If one follows the arrow of time from the early 1980s to the present day, the number of programming problems have not only proliferated but have also become more difficult. Fortunately  programming in itself has  become more manageable with massive increases in computing horsepower, smarter tools and instant availability of information on the internet, typically with the click of a mouse.

Learning to program is no easy task, but can be done with the right mix of attitude, curiosity and interest. Becoming adept at programming, however, is something else. An interesting essay in this context is Peter Norvig’s ‘Teach yourself programming in 10 years’

Back in the 1980s when I wrote my first Fortran program on my college Mainframe, programming was a lengthy exercise, spanning several days.

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My first program was to plot a sine wave of characters on a computer printout. Running this program required the following several steps

  1. Enter the program on a teletype terminal and create a stack of Hollerith (punched) cards
  2. Submit the stack of cards to the computer center
  3. The computer center would do a batch execute in the evening on the Mainframe
  4. God forbid, if your program has a syntax error. If you did find an error, go back to step 1, the next day.
  5. Assuming everything is fine, the computer center would run your program and your output (printout) would be placed in the appropriate pigeon hole which you would need to pick up the next day.

The whole exercise to write a small-sized program could take anywhere between a couple of days to a whole week.

In the early 1990s things got a little better where one could code, compile, link and execute sitting at one’s desk. However while the programming itself got much simpler than before, certain tasks were still difficult.  Till the late 90s programs of any sort had to be written using a regular text editor (vi , emacs etc.)  You would then have to go through the process of compiling, linking and executing.

An angry compiler would typically spew forth venom at missing semi-colons, undeclared variables, and uninitialized values. This would happen till you are able to iron out all syntax errors.  Then you would link, get undefined symbols and have to include appropriate libraries etc. And then finally you would execute your code, only to have it crash. The process of debugging would then start.

Luckily technology has made life a whole lot easier except for the last step where you could still  run into an execution errors . In these days an IDE (Interactive Development Environment) like Eclipse will flag syntax errors, missing definitions/declarations etc. as you write your code. Moreover Eclipse can also indicate which libraries (imports) you would need to include in your package for it to build. The only missing step in IDEs of these days is the ability to predict possible execution errors in your program.  I wouldn’t be surprised, if in future, like Microsoft Word,  the IDE is able to tell you if a programming construct does not make sense.

So things have gotten a lot easier for the programmer. The following tips for are particularly useful as you progress along in programming

  1. These days when you are learning a new programming language it is not necessary to know the language from cover to cover by reading a book. In those days when we learnt C it was necessary to know everything from bit structures, macros, pragma etc. The reason being that every syntax or execution error one had to rush to get the textbook and thumb through it for the answer. Not so, in these days of Google. You have the world’s library at your fingertips.
  2. To get started it is necessary to learn just the most important programming constructs of the language say structure, class, car, cdr besides the usual suspects like loops, conditions and case constructs
  3. Download and install an IDE for the language. In most case Eclipse will work
  4. Try to write a simple program and test out your code.
  5. To do any sort of programming these days you will necessarily need to make 3 friends
    1. Google
    2. Stackoverflow
    3. Git & GitHub
  6. Honing your Googling skills is very important. There are answers to almost any sort of programming problems out there. You would be surprised to know that there are many others who did exactly the same stupid mistake that you did out there. Also googling will take you to interesting tutorials, blogs, articles that discuss different aspects of the programming language and the problem you are trying to solve
  7. Stackoverflow is really a God send to all programmers. There are so many questions on so many aspects of every programming language on earth there. If you spend time searching Stackoverflow you are bound to find answers, code snippets that you can readily use in your code
  8. Post your questions in stackoverflow when you don’t find the answers there. You are bound to get quick answers. Thanks to the gamification of Stackoverflow (points, upvotes,badges  etc) that has been created on Stackoverflow.
  9. Git & GitHub: I would suggest that you download and install GitHub for Windows. This will provide you with version control on your desktop. You can modify code while being to switch back to an earlier version with Git. Read up a good tutorial on Git for Windows
  10. Once you have working code you push it onto GitHub and share with other programmers

Now that you have the basic setup here are few other extremely important tips

  1. The most important criteria for programming is ‘attitude’. Initially you are bound to get frustrated, angry, irritated etc. But it is necessary to look at the errors that you get with the right attitude. Know that an error is telling you something. Usually the answers to your mistake are in the ‘error message’ itself. Look at it closely and try to understand it. You will learn a lot more when you learn from errors than from copy-pasting from somebody else’s code, even if works right the first time around!
  2. Make sure you do something different each time. As Einstein said “ If you keep doing the same thing, you will keep getting the same result’
  3. There are different ways to debug your code. You could use the debugger and single step through the code and keep checking the values of the variables. I personally prefer print statements to localize where things are going wrong. I then try to narrow down the problem to a few lines of code and try to take it apart.

Hopefully the above tips are useful. Programming can be creative activity and will be indispensable in our future.

Above all have fun coding, there are so many possibilities these days!

Also see

1. Programming languages in layman’s language
2. The common alphabet of programming languages
3. The mind of the programmer
4. Programming Zen and now – Some essential tips -2 

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Programming Zen and now – Some essential tips-2

C Language – The code of God

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One could easily say “In the beginning there was C language. All else were variants” and not be far from the truth.  As I headed to work today I was ruminating on the impact C language has had to the computing landscape for the past 4 decades. No other language has had such a significant impact.

C Language was created by Dennis Ritchie & Brian Kernighan in Bell Labs, around 1972. C was the trigger for many seismic shifts in the computing industry. The language is terse and compact. C language strikes a rich balance between brevity and readability.

C language, in my opinion, is the code of God.

We can easily divide the epoch of programming languages as before C and after C. Before C, there was a babel of languages from FORTRAN, COBOL, Pascal, Basic, Prolog, Ada, Lisp and numerous others. When C language, entered the scene, many other languages simply faded away. C set the tone for programming and spawned an entire industry.

Many of the popular constructs like the if-then-else, for, while loops had a crisp simplicity in C. C included in its repertoire the ability to manipulate the bits of registers  all the way to creating complex and rich data structures with the help of structures and pointers. In fact C was probably one of key enablers for the development of the legendary Operating System (OS), UNIX from Bell Labs.

Building the innards of an OS is an undertaking of gigantic proportions and requires the need to be able to manipulate the registers of the numerous input/output devices, the processors and the memory.  C was eminently suited for this the job. Also the complex algorithms of OS for e.g. process scheduling, memory management, IO management, disk management could now be programed simultaneously in a bottom-up fashion by working at the ‘bit’ level and in a top-down fashion allowing for complex data structures and algorithms required for scheduling, memory and IO management. . With a powerful language C, the birth of UNIX was a given.  When AT&T distributed UNIX to the universities in the late 1970 it created serious shock waves in the industry. Since then UNIX has resulted in numerous variants – Solaris, HP-UX, AIX, iOS, Linux and then Android and so on. Well, that’s another story!

C came at an opportune time when the internet was at its infancy. C proceeded to be useful also for protocol of the internet namely TCP/IP. C spawned an army of programmers all keen to take on this new language twiddling bits, bytes and complex data structures of the OS and protocols.

C, UNIX and TCP/IP almost entirely power the internet and the WorldWideWeb.

The beauty and brevity of the language enabled programmers to easily express complex problems as units of C functions. Pointers, and bit manipulation gave it a power that was unparalleled at that time. Soon C became the de facto programming standard. C, in fact, became a way of thinking for problems!

So it was not surprising that languages that came after C used the same or similar constructs. C++ maintained identical constructs of C to maintain backward compatibility as well as to allow the already existing millions of C programmers easily assimilate the OO paradigm. Java, from Sun Micro Systems, followed suit.  Java, a very powerful and popular language, also retained the flavor of C.

Many interpreted and dynamic languages like Perl, Python, and Ruby all have C look-alike constructs,

Even in the languages of the Word Wide Web, C familiarity is extremely useful. JavaScript, PHP look familiar to one who is proficient in C.

The only other language which is entirely different from C from the bottom up, in my opinion is Lisp. Lisp is older than C and requires an entirely different way of thinking. There are possibly others too.

C balances economy of syntax, style and structure in programming exquisitely. It does have a few shortcomings, as its detractors would like to say. For e.g. C in the hands of a novice can spell disaster. It has also been accused of allowing programmers to create impregnable code. But in the hands of an experienced programmer it is possible to create really, robust code. UNIX and its variants are considered to be more resilient than OS’es to hackers.

C is really the soul of programming!

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