A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write.
Seeing Everything as an Object--Initially, Matz looked at other languages to find an ideal syntax. Recalling his search, he said, “I wanted a scripting language that was more powerful than Perl, and more object-oriented than Python3.”
In Ruby, everything is an object. Every bit of information and code can be given their own properties and actions. Object-oriented programming calls properties by the name instance variables and actions are known as methods. Ruby’s pure object-oriented approach is most commonly demonstrated by a bit of code which applies an action to a number.
Ruby’s Flexibility--Ruby is seen as a flexible language, since it allows its users to freely alter its parts. Essential parts of Ruby can be removed or redefined, at will. Existing parts can be added upon. Ruby tries not to restrict the coder.
For example, addition is performed with the plus (+) operator. But, if you’d rather use the readable word plus, you could add such a method to Ruby’s builtin Numeric class.Ruby’s operators are syntactic sugar for methods. You can redefine them as well.
Blocks, a Truly Expressive Feature--Ruby’s block are also seen as a source of great flexibility. A programmer can attach a closure to any method, describing how that method should act. The closure is called a block and has become one of the most popular features for newcomers to Ruby from other imperative languages like PHP or Visual Basic.
Blocks are inspired by functional languages. Matz said, “in Ruby closures, I wanted to respect the Lisp culture.
Ruby’s Visual Appearance--While Ruby often uses very limited punctuation and usually prefers English keywords, some punctuation is used to decorate Ruby. Ruby needs no variable declarations. It uses simple naming conventions to denote the scope of variables.
var could be a local variable.
@var is an instance variable.
$var is a global variable.
These sigils enhance readability by allowing the programmer to easily identify the roles of each variable. It also becomes unnecessary to use a tiresome self. prepended to every instance member.
Beyond the Basics--Ruby has a wealth of other features, among which are the following:
Ruby has exception handling features, like Java or Python, to make it easy to handle errors.
Ruby features a true mark-and-sweep garbage collector for all Ruby objects. No need to maintain reference counts in extension libraries. As Matz says, “This is better for your health.”
Writing C extensions in Ruby is easier than in Perl or Python, with a very elegant API for calling Ruby from C. This includes calls for embedding Ruby in software, for use as a scripting language. A SWIG interface is also available.
Ruby can load extension libraries dynamically if an OS allows.
Ruby features OS independent threading. Thus, for all platforms on which Ruby runs, you also have multithreading, regardless of if the OS supports it or not, even on MS-DOS!
Ruby is highly portable: it is developed mostly on GNU/Linux, but works on many types of UNIX, Mac OS X, Windows 95/98/Me/NT/2000/XP, DOS, BeOS, OS/2, etc.