IRB - Useful commands

IRB - Useful commands

$ IRB   ****Let you into Ruby Interpreter

1.9.3-p194 :088 >  use TAB key to autocomplete. 

1.9.3-p194 :089 > help

Enter the method name you want to look up.
You can use tab to autocomplete.
Enter a blank line to exit.

>> AbstractController

######
loading a file.rb
######

1.9.3-p194 :053 > load 'ruby_script.rb'

1.9.3-p194 :053 > aSong = Song.new 

1.9.3-p194 :053 > aSong.methods
 => [:name, :name=, :artist, :artist=, :duration, :duration=, :to_s, ....

1.9.3-p194 :053 > aSong.instance_variables 
 => [:@name, :@artist, :@duration, :@plays] 

1.9.3-p194 :062 > aSong.class
 => Song 

############
Searching a method in your obj, eg aSong
############
1.9.3-p194 :053 > aSong.methods.grep(/ar/)
 => [:artist, :artist=, :instance_variables, :instance_variable_get, :instance_variable_set, :instance_variable_defined?] 

############
Searching a all Array, Harshes, String Methods 
############
1.9.3-p194 :064 > [].methods
 => [:inspect, :to_s, :to_a, :to_ary, :frozen?, :==, :eql?,

1.9.3-p194 :066 > {}.methods
 => [:rehash, :to_hash, :to_a, :inspect, :to_s, :==, :[],

1.9.3-p194 :067 > String.methods 
 => [:try_convert, :allocate, :new, :superclass, :freeze, :===, :==,  

###########
Using grep in your searches
##########
1.9.3-p194 :069 > [].methods.grep(/^re/)
 => [:reverse_each, :reverse, :reverse!, :reject, :reject!, :replace, 

###########
Using helping to lookup method, hashes, string
##########
 1.9.3-p194 :072 > [].methods --help

Enter the method name you want to look up.
You can use tab to autocomplete.
Enter a blank line to exit.

>> replace

############
Rails Method name Lookup. Starts with a hash tag. eg. #action_method
###########

1.9.3-p194 :015 > help
Enter the method name you want to look up.
You can use tab to autocomplete.
Enter a blank line to exit.

>> a  #type a to displays  all record eg. beginning with a
AbstractController::Base#action_methods   
AbstractController::Base#available_action?
AbstractController::Base::abstract
AbstractController::Base::abstract!
AbstractController::Base::abstract?....
 
>> AbstractController::Base #type to displays  all class methods and instance Methods   

AbstractController::Base < Object

------------------------------------------------------------------------------
Includes:
ActiveSupport::Configurable (from gem actionpack-3.2.8)

(from gem actionpack-3.2.8)
------------------------------------------------------------------------------
AbstractController::Base is a low-level API. Nobody should be using it
directly, and subclasses (like ActionController::Base) are expected to provide
their own render method, since rendering means different things
depending on the context.
------------------------------------------------------------------------------
Class methods:

  abstract
  abstract!
  abstract?
  action_methods
  clear_action_methods!
  controller_path
  hidden_actions
  internal_methods
  method_added

Instance methods:

  action_methods
  available_action?
  controller_path
  process

Attributes:

  attr_reader abstract
  attr_reader abstract?

>>Object, Array, Class, Hash