About Application Programming Interface? Please read below?

[Heni Y]

Hi,
I really tried to understand API but I don't know much about it. What is your short definition of it? How can I develop applications using any websites API, like twitter API? I mean what "programming languages" do I have to know before I can develop any application? THANK YOU!

[Trizzle]

when you stop being a n00b you will understand.

[joe.attaboy]

The programming language you use will depend on what language(s) is/are supported by the API.

An API is term that describes the programming libraries and other tools that provide hooks into a web application. For example, the Twitter developers have packaged up a bunch of classes and libraries that independent programmers would have to use in their code to access certain Twitter site functions.

[KingHumpty]

An API is just the interface specification of a ready-to-go set of program units that you may reuse for your own software (so long as the libraries are available on the machines your program will run on).

Essentially, the API is the function headers (the name of the function and it's parameter list + any comments on it if they exist).

For an example of a particularly well written API, see the java API spec here:

http://java.sun.com/javase/6/docs/api/

That's a good example of the kind of information that you get in an API. Most, however, are not so informative (ranging from one like java's, to things which are downright useless).

As for the "programming languages" you need, these will differ as to what API you are using. I'd say, however, that if you started learning HTML and/or XHTML you'd not be wasting your time. You could then start to head into various web scripting languages.

However, as a point of pedantry, not all languages with which one programs with are actually called "programming languages", because not all languages (eg xml or basic SQL) are actually Turing complete - which is part of the requirements for a language to be an actual "programming language". XML is a data description language (since all it does is provide a means to describe a data structure) and SQL is a query language (since all you can do with it is form database queries - although SQL is much closer to being a programming language, it just falls short of being complete enough for it). Anyway, you don't really need to worry about that so much at this stage (although if you ever study Comp' science ... you will meet it )

[?]

An API is an INTERFACE for APPLICATION PROGRAMMERS

Therefore a PROGRAMMER can write APPLICATIONS that can INTERFACE with the "twitter" system.