What's the difference between a string and a symbol in Ruby? Constants defined inside the class can be accessed inside the class and those defined inside the modules can be accessed inside the modules, we can also define the constant as the global which outside the class and module and will be available for all. Variables are often easier to remember and type than the actual information we are working with (e.g. user3 = UserClass.new("2", "Sujoy", "T nagar, Chennai") Making an assignment to a constant that is already initialized produces a warning. Symbols look better, they are immutable & if you benchmark string keys vs symbols keysyou will find that string keys are about 1.70x slower. Examples. You can substitute the value of any Ruby expression into a string using the sequence #{ expr }. end We finally created objects from the UserClass and with the initialized object(instance) we are calling the function show_detail. Here $global_variable is a global variable. This will produce the following result −. ALL RIGHTS RESERVED. Here, @cust_id, @cust_name and @cust_addr are instance variables. A symbol looks like a variable declaration without a value. — patient_addressvs ‘1234 Amityville Lane, Apt 3., Anytown, New York, 67890’). :language.to_s # "language" This comes in handy if you need to display a Symbol and want to transform how it looks. Important methods: 1. size 2. empty? Programmers assign pieces of data to variables for many reasons, but I will list a few of the main ones so that you have a very general understanding: 1. Following is the list of Backslash notations supported by Ruby −. A trailing comma is ignored. What’s A Ruby Variable? Ruby Pseudo-Variables. Variables give a label to an object. Used to represent text & data. Start Your Free Software Development Course, Web development, programming languages, Software testing & others. puts "constant first value is  #{CONSTANT1}" Variables and symbols are different things. Here, expr could be any ruby expression. puts "User name is #@user_name" Example: The :title after attr_reader is a symbol that represents the @title instance variable. Assignment to uninitialized local variables also serves as variable declaration. In Ruby, a symbol is more like a string than a variable. puts "RubyClass2 global variable output is  #$ruby_global_variable" Class variables begin with @@ and must be initialized before they can be used in method definitions. def initialize(user_id, user_name, address) In effect, at program setup, this table is filled in with all the methods, variables and classes included in the Ruby… Symbols are a special, limited variation of Strings. object.display_constant. Example: In the below example we have defined a variable $ruby_global and it can be accessed inside the two classes called RubyClass1 and RubyClass2. # Call the Methods of class for displaying the details Constants are variables that holds the same value throughout the program. def show_details() You can also get the integer value, corresponding to an ASCII character or escape the sequence by preceding it with a question mark. A trailing comma is ignored. An integer number can range from -230 to 230-1 or -262 to 262-1. Example: The benefits? This will produce the following result −. Here we discuss ruby variables along with the available constant and its different types of variables they are global, local, instance, constant, and a class variable. s = :something The simplest way to convert it to a String is by using the Symbol#to_s method:. Symbols are more like strings, except that they're immutable and interned in memory, so that multiple references to the same symbol don't use extra memory. First, we defined a class with the name User, this class contains the initializations for the three variables. puts "RubyClass1 global variable output is  #$ruby_global_variable" @user_id = user_id def total_users() The following is a simple example of a symbol literal in Ruby: :symbol Integer corresponding identifiers, variable names, and operators.

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