What does the symbol mean in Ruby?

Symbol is the most basic Ruby object we can create. It’s just a name and an internal ID. Since a given symbol name refers to the same object throughout a Ruby program, Symbols are useful and more efficient than strings.

What do double colons mean Ruby?

The :: is a unary operator that allows: constants, instance methods and class methods defined within a class or module, to be accessed from anywhere outside the class or module.

What does \%I mean in Ruby?

Lowercase \%i stands for. Non-interpolated Array of symbols, separated by whitespace (after Ruby 2.0) In addition, uppercase \%I means. Interpolated Array of symbols, separated by whitespace (after Ruby 2.0)

What does @variable mean in Ruby?

In Ruby, the at-sign ( @ ) before a variable name (e.g. @variable_name ) is used to create a class instance variable. These variables are: Specific to each instantiated object of the class they’re defined in (i.e. each class object instance has a separate copy of these variables).

How do you inherit a class in Ruby?

Use of super Method in Inheritance: This method is used to call the parent class method in the child class. If the method does not contain any argument it automatically passes all its arguments.

What does the 1/10 indicate in Ruby?

What does the 1… 10 indicate? Explanation: 1… 10 means start from one and go till 9 and don’t include 10.

What is namespace in Ruby?

A namespace is a container for multiple items which includes classes, constants, other modules, and more. The namespace in Ruby is defined by prefixing the keyword module in front of the namespace name. The name of namespaces and classes always start from a capital letter.

What is module in Ruby?

A Module is a collection of methods, constants, and class variables. Modules are defined as a class, but with the module keyword not with class keyword. Important Points about Modules: You cannot inherit modules or you can’t create a subclass of a module. Objects cannot be created from a module.

What is freeze in Ruby?

The freeze method in Ruby is used to ensure that an object cannot be modified. This method is a great way to create immutable objects. Any attempt to modify an object that has called the freeze method will result in the program throwing a runtime error.

What does N mean in Ruby?

Escape sequences. Besides quotes, there are more symbols we can escape in strings. For example, a newline is represented by \n . This is called an “escape sequence”.

What does Attr_accessor mean in Ruby?

attr_accessor is used to define an attribute for object of Model which is not mapped with any column in database. This answers question – What is attr_accessor in Rails.

What does .NEW mean in Ruby?

The important bit to learn for you is: the method initialize is a special method with a special meaning in Ruby: Whenever you call the method new on a class, as in Person. new , the class will create a new instance of itself. It will then, internally, call the method initialize on the new object.

What are dot and double colon operators in Ruby?

Ruby dot and double Colon Operators: In Ruby you call a module method by preceding its name with the module’s name and a period and you refer a constant using the module name and two colons. The :: is a unary operator and is used to access constants, instance methods and class methods defined within a class or module.

What is this double-colon ::?

What is this double-colon ::? E.g. Foo::Bar. The :: is a unary operator that allows: constants, instance methods and class methods defined within a class or module, to be accessed from anywhere outside the class or module. What good is scope (private, protected) if you can just use :: to expose anything?

What is the use of :: operator in Ruby?

Ruby . and :: operators. In Ruby you call a module method by preceding its name with the module’s name and a period and you refer a constant using the module name and two colons. The :: is a unary operator and is used to access (anywhere outside the class or module) constants, instance methods and class methods defined within a class or module.

What is constant lookup in Ruby?

As Matz delineates in his book, ‘The Ruby Programming Language’, constant lookup has multiple steps. First, it searches a constant in the lexical scope where the constant is referenced.