Determining type of an object in ruby

Question

I ll use python as an example of what I m looking for  you can think of it as pseudocode if you don t know Python     gt  gt  gt  a   1  gt  gt  gt  type a   lt type  int  gt    I know in ruby I can do    1 9 3p194  002  gt  1 class    gt  Fixnum    But is this the proper way to determine the type of the object

User · Answer

you could also try  instance of   p 1 instance of  Fixnum       gt  True p  1  instance of  String     gt  True p  1 2  instance of  Array    gt  True

User · Answer

The proper way to determine the  type  of an object  which is a wobbly term in the Ruby world  is to call object class   Since classes can inherit from other classes  if you want to determine if an object is  of a particular type  you might call object is a  ClassName  to see if object is of type ClassName or derived from it   Normally type checking is not done in Ruby  but instead objects are assessed based on their ability to respond to particular methods  commonly called  Duck typing   In other words  if it responds to the methods you want  there s no reason to be particular about the type   For example  object is a  String  is too rigid since another class might implement methods that convert it into a string  or make it behave identically to how String behaves  object respond to   to s  would be a better way to test that the object in question does what you want

User · Answer

I would say  Yes   As  Matz  had said something like this in one of his talks    Ruby objects have no types    Not all of it but the part that he is trying to get across to us   Why would anyone have said   Everything is an Object  then   To add he said  Data has Types not objects    So we might enjoy this   https   www youtube com watch v 1l3U1X3z0CE  But Ruby doesn t care to much about the type of object just the class   We use classes not types  All data then has a class    12345 class   my string  class   They may also have ancestors  Object ancestors   They also have meta classes but I ll save you the details on that   Once you know the class then you ll be able to lookup what methods you may use for it  That s where the  data type  is needed  If you really want to get into details the look up      The Ruby Object Model   This is the term used for how Ruby handles objects  It s all internal so you don t really see much of this but it s nice to know  But that s another topic   Yes  The class is the data type  Objects have classes and data has types  So if you know about data bases then you know there are only a finite set of types   text blocks numbers

User · Answer

variable name class Here variable name is  quot a quot  a class

User · Answer

Oftentimes in Ruby  you don t actually care what the object s class is  per se  you just care that it responds to a certain method  This is known as Duck Typing and you ll see it in all sorts of Ruby codebases   So in many  if not most  cases  its best to use Duck Typing using  respond to  method    object respond to   to i

[ruby] Determining type of an object in ruby

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