Best Ruby on Rails Tutorial: we will discuss Ruby on Rails (ROR).
1. What is Ruby on Rails?
a) A programming language
b) An operating system
c) A web application framework
d) A database management system
Answer: c) A web application framework
2. Which command is used to create a new Rails application?
a) rails new
b) rails create
c) rails generate
d) rails build
Answer: a) rails new
3. What is the purpose of migrations in Ruby on Rails?
a) To handle user authentication
b) To create database tables and modify their structure
c) To manage web requests and responses
d) To handle session management
Answer: b) To create database tables and modify their structure
4. Which file is used to define the routes in a Rails application?
a) routes.rb
b) application.rb
c) environment.rb
d) config.rb
Answer: a) routes.rb
5. What is the convention for naming a Rails model that represents a table called “users”?
a) UsersModel
b) UserModel
c) User
d) Users
Answer: c) User
6. What is the purpose of the Rails console?
a) To execute SQL queries directly on the database
b) To interact with the Rails application and execute Ruby code
c) To manage the server configurations
d) To deploy the Rails application to a production server
Answer: b) To interact with the Rails application and execute Ruby code
7. Which command is used to generate a new controller in Rails?
a) rails new
b) rails create
c) rails generate controller
d) rails build controller
Answer: c) rails generate controller
8. What is the default database used by Rails?
a) MySQL
b) PostgreSQL
c) SQLite
d) MongoDB
Answer: c) SQLite
9. Which file is used to define the database configuration in Rails?
a) application.yml
b) database.yml
c) config.yml
d) environment.rb
Answer: b) database.yml
10. What is the purpose of the “params” hash in Rails?
a) To store session information
b) To handle user authentication
c) To store form input values and URL parameters
d) To manage database connections
Answer: c) To store form input values and URL parameters
11. What is the purpose of the “before_action” method in a Rails controller?
a) It defines a callback method that is executed before each action in the controller.
b) It defines a method that is executed after each action in the controller.
c) It defines a filter that restricts access to certain actions in the controller.
d) It defines a method that is executed before rendering the view in the controller.
Answer: a) It defines a callback method that is executed before each action in the controller.
12. Which of the following is NOT a valid association type in Rails?
a) has_many
b) belongs_to
c) has_and_belongs_to_many
d) has_one_to_one
Answer: d) has_one_to_one
13. What is the purpose of the “render” method in Rails?
a) To redirect the user to another page.
b) To render a view template.
c) To send an HTTP response.
d) To execute a database query.
Answer: b) To render a view template.
14. Which command is used to run database migrations in Rails?
a) rails migrate
b) rails run_migrations
c) rake db:migrate
d) rake db:run_migrations
Answer: c) rake db:migrate
15. What is the purpose of the “flash” in Rails?
a) To store temporary session data that is available across requests.
b) To display error messages to the user.
c) To manage user authentication.
d) To handle file uploads in a Rails application.
Answer: a) To store temporary session data that is available across requests.
16. What is the purpose of the “gemfile” in a Rails application?
a) To define the application’s database schema.
b) To manage the application’s dependencies.
c) To configure the application’s routes.
d) To define the application’s models.
Answer: b) To manage the application’s dependencies.
17. Which of the following is NOT a valid Rails testing framework?
a) RSpec
b) Cucumber
c) Capybara
d) Django
Answer: d) Django
18. What is the purpose of the “yield” keyword in a Rails layout file?
a) To define a block of content that can be overridden in child views.
b) To insert the content of a partial view into the layout.
c) To define a placeholder for dynamic content.
d) To render the view template within the layout.
Answer: d) To render the view template within the layout.
19. How can you secure sensitive information such as API keys in a Rails application?
a) Storing them directly in the source code.
b) Encrypting them using a custom encryption algorithm.
c) Storing them in environment variables.
d) Writing them to a separate configuration file.
Answer: c) Storing them in environment variables.
20. What is the purpose of the Rails asset pipeline?
a) To optimize the loading of JavaScript and CSS assets.
b) To generate static HTML files for faster rendering.
c) To manage database migrations.
d) To handle user authentication and authorization.
Answer: a) To optimize the loading of JavaScript and CSS assets.
21. What is the purpose of the “has_secure_password” method in a Rails model?
a) To encrypt user passwords before storing them in the database.
b) To validate the password complexity and length.
c) To handle user authentication and password hashing.
d) To manage user sessions and cookies.
Answer: c) To handle user authentication and password hashing.
22. What is the purpose of the Rails asset pipeline?
a) To optimize the loading of JavaScript and CSS assets.
b) To generate static HTML files for faster rendering.
c) To manage database migrations.
d) To handle user authentication and authorization.
Answer: a) To optimize the loading of JavaScript and CSS assets.
23. What is the purpose of the “belongs_to” association in Rails?
a) To define a one-to-one relationship between two models.
b) To define a one-to-many relationship between two models.
c) To define a many-to-many relationship between two models.
d) To define a polymorphic association between two models.
Answer: b) To define a one-to-many relationship between two models.
24. What is the purpose of the “params.require” method in a Rails controller?
a) To permit and retrieve specific parameters from the request.
b) To validate the presence of certain parameters in the request.
c) To sanitize and filter the parameters before using them.
d) To require authentication before processing the request.
Answer: a) To permit and retrieve specific parameters from the request.
25. Which command is used to start the Rails server?
a) rails start
b) rails server
c) rails run
d) rails launch
Answer: b) rails server
26. What is the purpose of the “respond_to” method in a Rails controller?
a) To define the MIME types that the controller can respond to.
b) To handle HTTP request methods like GET, POST, etc.
c) To specify the layout to be used for rendering the view.
d) To define the routes for the controller actions.
Answer: a) To define the MIME types that the controller can respond to.
27. Which command is used to generate a new migration file in Rails?
a) rails generate migration
b) rails new migration
c) rails create migration
d) rails build migration
Answer: a) rails generate migration
28. What is the purpose of the “has_many :through” association in Rails?
a) To define a one-to-many relationship with a join table.
b) To define a many-to-many relationship with a join table.
c) To define a one-to-one relationship with a foreign key.
d) To define a polymorphic association with multiple models.
Answer: b) To define a many-to-many relationship with a join table.
29. Which command is used to run Rails tests?
a) rails test
b) rails run tests
c) rails execute tests
d) rails start testing
Answer: a) rails test
30. What is the purpose of the “gem” command in Rails?
a) To install and manage RubyGems in the Rails application.
b) To handle database migrations and schema changes.
c) To manage the application’s routing configurations.
d) To generate new controllers and models in the Rails application.
Answer: a) To install and manage RubyGems in the Rails application.
31. What is the purpose of the “has_one” association in Rails?
a) To define a one-to-one relationship between two models.
b) To define a one-to-many relationship between two models.
c) To define a many-to-many relationship between two models.
d) To define a polymorphic association between two models.
Answer: a) To define a one-to-one relationship between two models.
32. Which directory in a Rails application is used to store JavaScript and CSS files?
a) app/controllers
b) app/models
c) app/views
d) app/assets
Answer: d) app/assets
33. What is the purpose of the “has_and_belongs_to_many” association in Rails?
a) To define a one-to-one relationship between two models.
b) To define a one-to-many relationship between two models.
c) To define a many-to-many relationship between two models.
d) To define a polymorphic association between two models.
Answer: c) To define a many-to-many relationship between two models.
34. Which command is used to run Rails database seeds?
a) rails seed
b) rails run_seed
c) rake db:seed
d) rake db:run_seed
Answer: c) rake db:seed
35. What is the purpose of the “partials” in Rails views?
a) To define layouts for the application.
b) To render shared sections of views across different templates.
c) To define model associations and relationships.
d) To encapsulate business logic within the views.
Answer: b) To render shared sections of views across different templates.
36. What is the purpose of the “validates” method in a Rails model?
a) To define associations between models.
b) To perform database validations for model attributes.
c) To define custom SQL queries.
d) To handle model inheritance.
Answer: b) To perform database validations for model attributes.
37. Which command is used to generate a new migration to add a column to an existing table in Rails?
a) rails generate migration
b) rails new migration
c) rails add_column
d) rails migration add
Answer: a) rails generate migration
38. What is the purpose of the “form_for” helper in Rails views?
a) To create a form element for submitting data to the server.
b) To define routes for RESTful resources.
c) To handle user authentication and authorization.
d) To execute SQL queries on the database.
Answer: a) To create a form element for submitting data to the server.
39. Which command is used to generate a new Rails scaffold?
a) rails generate scaffold
b) rails create scaffold
c) rails build scaffold
d) rails new scaffold
Answer: a) rails generate scaffold
40. What is the purpose of the Rails application layout file?
a) To define the overall structure and appearance of the application.
b) To handle database migrations and schema changes.
c) To define the application’s routes.
d) To handle user authentication and authorization.
Answer: a) To define the overall structure and appearance of the application.
41. What is the purpose of the “polymorphic” association in Rails?
a) To define a one-to-one relationship between two models.
b) To define a one-to-many relationship between two models.
c) To define a many-to-many relationship between two models.
d) To define a relationship that can belong to multiple models.
Answer: d) To define a relationship that can belong to multiple models.
42. Which command is used to generate a new Rails migration to remove a column from an existing table?
a) rails generate migration
b) rails new migration
c) rails remove_column
d) rails migration remove
Answer: a) rails generate migration
43. What is the purpose of the “link_to” helper in Rails views?
a) To create a hyperlink to a specific URL or route.
b) To define associations between models.
c) To handle form submissions.
d) To execute database queries.
Answer: a) To create a hyperlink to a specific URL or route.
44. Which command is used to generate a new Rails controller with only specific actions?
a) rails generate controller
b) rails new controller
c) rails create controller
d) rails scaffold controller
Answer: a) rails generate controller
45. What is the purpose of the “before_validation” callback in a Rails model?
a) To perform an action before saving the model to the database.
b) To validate the presence and format of model attributes.
c) To handle file uploads in the model.
d) To define associations between models.
Answer: a) To perform an action before saving the model to the database.
46. What is the purpose of the Rails helper methods?
a) To perform common tasks and provide reusable functionality in views.
b) To define the application’s database schema.
c) To handle database migrations and schema changes.
d) To handle user authentication and authorization.
Answer: a) To perform common tasks and provide reusable functionality in views.
47. Which command is used to run Rails console in sandbox mode?
a) rails console
b) rails sandbox
c) rails run_console
d) rails console –sandbox
Answer: d) rails console –sandbox
48. What is the purpose of the “collection_select” helper in Rails views?
a) To create a dropdown menu for selecting a single item from a collection.
b) To display a collection of records in a tabular format.
c) To handle form submissions.
d) To generate URLs for RESTful resources.
Answer: a) To create a dropdown menu for selecting a single item from a collection.
49. Which command is used to generate a new Rails migration to rename a column in an existing table?
a) rails generate migration
b) rails new migration
c) rails rename_column
d) rails migration rename
Answer: a) rails generate migration
50. What is the purpose of the “has_many :through” association in Rails?
a) To define a one-to-one relationship with a join table.
b) To define a many-to-many relationship with a join table.
c) To define a one-to-many relationship with a foreign key.
d) To define a polymorphic association with multiple models.
Answer: b) To define a many-to-many relationship with a join table.
51. What is the purpose of the “scope” method in a Rails model?
a) To define a query that can be reused throughout the application.
b) To define a named route for a specific action in the controller.
c) To define a callback method that is executed before saving the model.
d) To define a method that calculates a derived attribute based on other model attributes.
Answer: a) To define a query that can be reused throughout the application.
52. Which command is used to generate a new Rails migration to create a new table?
a) rails generate migration
b) rails new migration
c) rails create_table
d) rails migration create
Answer: a) rails generate migration
53. What is the purpose of the “form_tag” helper in Rails views?
a) To create a form element for submitting data to the server.
b) To define routes for RESTful resources.
c) To handle user authentication and authorization.
d) To execute SQL queries on the database.
Answer: a) To create a form element for submitting data to the server.
54. Which command is used to generate a new Rails mailer?
a) rails generate mailer
b) rails new mailer
c) rails create mailer
d) rails build mailer
Answer: a) rails generate mailer
55. What is the purpose of the “accepts_nested_attributes_for” method in a Rails model?
a) To define a relationship between nested resources.
b) To define strong parameters for nested attributes in a form.
c) To define nested routes for related resources.
d) To define nested layouts for views.
Answer: b) To define strong parameters for nested attributes in a form.
56. What is the purpose of the “has_one :through” association in Rails?
a) To define a one-to-one relationship through a join table.
b) To define a many-to-many relationship through a join table.
c) To define a one-to-many relationship through a foreign key.
d) To define a polymorphic association through multiple models.
Answer: a) To define a one-to-one relationship through a join table.
57. Which command is used to generate a new Rails migration to add an index to a table column?
a) rails generate migration
b) rails new migration
c) rails add_index
d) rails migration add
Answer: c) rails add_inde
58. What is the purpose of the “render” method in a Rails controller?
a) To define the layout for the view.
b) To handle form submissions.
c) To render a view template or partial.
d) To execute database queries.
Answer: c) To render a view template or partial.
59. Which command is used to generate a new Rails helper?
a) rails generate helper
b) rails new helper
c) rails create helper
d) rails build helper
Answer: a) rails generate helper
60. What is the purpose of the “enum” attribute in a Rails model?
a) To define associations between models.
b) To handle user authentication and authorization.
c) To specify a predefined list of values for an attribute.
d) To handle file uploads in the model.
Answer: c) To specify a predefined list of values for an attribute.
61. What is the purpose of the “find_by” method in Rails?
a) To find a record by a specific attribute value.
b) To find all records that match a specific condition.
c) To find the first record that matches a specific condition.
d) To find the last record that matches a specific condition.
Answer: a) To find a record by a specific attribute value.
62. Which command is used to generate a new Rails migration to rename a table?
a) rails generate migration
b) rails new migration
c) rails rename_table
d) rails migration rename
Answer: c) rails rename_table
63. What is the purpose of the “render json” method in a Rails controller?
a) To render a JSON response from the controller action.
b) To handle form submissions.
c) To define associations between models.
d) To execute database queries.
Answer: a) To render a JSON response from the controller action.
64. Which command is used to generate a new Rails model?
a) rails generate model
b) rails new model
c) rails create model
d) rails build model
Answer: a) rails generate model
65. What is the purpose of the “dependent” option in a Rails association?
a) To specify the foreign key for the association.
b) To define the type of association (e.g., has_many, belongs_to).
c) To define the order in which records are retrieved.
d) To specify the behavior when associated records are deleted.
Answer: d) To specify the behavior when associated records are deleted.
66. What is the purpose of the “has_secure_password” method in a Rails model?
a) To define a one-to-one relationship between two models.
b) To handle user authentication and password encryption.
c) To define a many-to-many relationship between two models.
d) To define a polymorphic association between two models.
Answer: b) To handle user authentication and password encryption.
67. Which command is used to generate a new Rails migration to add an index to multiple table columns?
a) rails generate migration
b) rails new migration
c) rails add_index
d) rails migration add
Answer: c) rails add_index
68. What is the purpose of the “yield” keyword in Rails views?
a) To define the layout for the view.
b) To handle form submissions.
c) To execute a block of code passed from a layout or partial.
d) To execute database queries.
Answer: c) To execute a block of code passed from a layout or partial.
69. Which command is used to generate a new Rails integration test?
a) rails generate integration_test
b) rails new integration_test
c) rails create integration_test
d) rails build integration_test
Answer: a) rails generate integration_test
70. What is the purpose of the “belongs_to” association in Rails?
a) To define a one-to-one relationship with a foreign key.
b) To define a one-to-many relationship with a foreign key.
c) To define a many-to-many relationship with a join table.
d) To define a polymorphic association with multiple models.
Answer: a) To define a one-to-one relationship with a foreign key.
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