How to really master a programming language

programming-languages

I know that learning a language, you can simply buy a book, follow the examples, and whenever possible try the exercises. But what I'm really looking is how to master the language once you've learned it.

Now I know that experience is one major factor, but what about learning the internals of the language, what is the underlying structure, etc.

There are articles out there saying read this book, read that book, make this game and that game.
But to me this doesn't mean to master a language. I want to be able to read other people's code and understand it, no matter how hard that is. To understand when to use a function and when another, etc etc.

The list could go on and on but I believe I've made the point. 🙂

And finally, take whatever language as an example if needed, though best would be if C was taken as an example.

Best Answer

I have to answer, "All of the above." People argue about whether coding is an art, a craft, an engineering discipline, or a branch of mathematics, and I think it's fairest to say it's some of each. As such, the more techniques you bring to mastery of the language, the better. Here is a partial list:

Use the language all day, every day. Usually this means being full-time employed in the language.
Read all you can about the language. Especially, "best practices" and idioms.
Join a users group to talk with others about the language and what they do with it.
Work with other people's code! There is no faster way to learn what not to do in a language than to have to clean up after someone who did something awful.
Support the code you write - every bug becomes a tour of your worst decisions!
Study computer science and languages in general
Learn a very different language. A great compliment to C would be a functional language like Lisp. This will turn the way you think about your procedural language inside out.
Learn to use the frameworks and APIs available for that language.
Take the time to do your own experiments with the language. SICP is not applicable to C, but the attitude of learning a language by testing its limits is a very productive one.
Read the history of the language to learn why it was made the way it is.
Attend conferences to hear the language authors speak, or to hear what industry leaders are doing with the language.
Take a class in the language.
Teach the language to others (thanks to Bryan Oakley)

In summary, do everything you can think of. There is no way to know everything about most languages. Every learning technique you use brings an additional perspective to your understanding.

Related Solutions

Functional Programming – How to Manage Without Assignment Statements

If there is no assignment statement,how can this be done?How to change the balance variable?

You can't change variables without some sort of assignment operator.

I ask so because I know there are some so-called pure functional languages out there and according to the Turing complete theory,this must can be done too.

Not quite. If a language is Turing complete that means that it can calculate anything that the any other Turing complete language can calculate. It doesn't mean that it has to have every feature other languages have.

It's not a contradiction that a Turing complete programming language has no way of changing the value of a variable, as long as for every program that has mutable variables, you can write an equivalent program that does not have mutable variables (where "equivalent" means that it calculates the same thing). And in fact every program can be written that way.

Regarding your example: In a purely functional language you simply wouldn't be able to write a function that returns a different account balance each time it's called. But you'd still be able to rewrite every program, that uses such a function, in a different way.

Since you asked for an example, let's consider an imperative program that uses your make-withdraw function (in pseudo-code). This program allows the user to withdraw from an account, deposit to it or query the amount of money in the account:

account = make-withdraw(0)
ask for input until the user enters "quit"
    if the user entered "withdraw $x"
        account(x)
    if the user entered "deposit $x"
        account(-x)
    if the user entered "query"
        print("The balance of the account is " + account(0))

Here's a way to write the same program without using mutable-variables (I won't bother with referentially transparent IO because the question wasn't about that):

function IO_loop(balance):
    ask for input
    if the user entered "withdraw $x"
        IO_loop(balance - x)
    if the user entered "deposit $x"
        IO_loop(balance + x)
    if the user entered "query"
        print("The balance of the account is " + balance)
        IO_loop(balance)
    if the user entered "quit"
        do nothing

 IO_loop(0)

The same function could also be written without using recursion by using a fold over the user input (which would be more idiomatic than explicit recursion), but I don't know whether you're familiar with folds yet, so I wrote it in a way that doesn't use anything you don't know yet.

When Can You Say You’ve Learned a Programming Language?

At what point can you say that you've "learned" a language like English or French? I think most people would accept that you've learned a language when you can use it to communicate. You don't have to know every word or understand every idiom, but you should know most of the (rather small) subset of the language that people use in daily conversation. Having "learned" a language to that extent, you can continue to learn more as you use the language daily and expose yourself to more and more of it. By the time you die, you still won't know all there is to know about the language, but nobody will say that you never "learned" the language.

So it is, I think, with computer languages. You can say that you "know" a language like C++ or Ruby when you can write useful programs in it. If you need to quantify the degree to which you know the language, use the same terms that you'd use for a human language. Say "I know a little C++" or "I know conversational C++" or "I'm fluent in C++" to mean that you know just enough to scrape by, enough to get useful things done, or that you're an expert, respectively.