Ruby

► Ruby uses the super keyword to call the superclass implementation of the current method.

► Within the body of a method, calls to super acts just like a call to that original method.

► The search for a method body starts in the superclass of the object that was found to contain the original method.

def url=(addr)

super (addr.blank? || addr.starts_with?('http')) ? addr : http://#{addr}

end

► Interpolation is the process of inserting a string into a literal.

► You can interpolate a string into a literal by placing a Hash (#) within {} open and close brackets.

► This refers to a new name to by referring to the copy of the original method.

RUBYOPT

Additional command-line options to Ruby; examined after real command-line options are parsed ($SAFE must be 0).

RUBYLIB

Additional search path for Ruby programs ($SAFE must be 0).

RUBYPATH

With -S option, search path for Ruby programs (defaults to PATH).

RUBYSHELL

Shell to use when spawning a process; if not set, will also check SHELL or COMSPEC. DLN_LIBRARY_PATH Search path for dynamically loaded modules.

RUBYLIB_PREFIX

(Windows only) Mangle the RUBYLIB search path by adding this prefix to each component.

► Ruby on Rails is an open source web application framework for the Ruby programming language.

► It is used with an Agile development methodology that is used by web developers for rapid development.

► The Ruby standard library extends the foundation of the Ruby built-in library with classes and abstractions for a variety of programming needs, including network programming, operating system services, threads, and more.

► These classes provide flexible capabilities at a high level of abstraction, giving you the ability to create powerful Ruby scripts useful in a variety of problem domains.

► Ruby is an object oriented language and every object oriented language tends to allocate many objects during execution of the program.

► Ruby deletes unallocated and unused objects automatically.

► This feature can be controlled by applying proper syntax and program through ruby.