Plateforme d'apprentissage pour la preparation aux entretiens, les tests en ligne, les tutoriels et la pratique en direct

Developpez vos competences grace a des parcours cibles, des tests blancs et un contenu pret pour l'entretien.

WithoutBook rassemble des questions d'entretien par sujet, des tests pratiques en ligne, des tutoriels et des guides de comparaison dans un espace d'apprentissage reactif.

Rechercher dans la bibliotheque

Preparation a l'entretien

Ruby On Rails Questions et reponses d'entretien

Question 66. Describe the difference between class and instance variables?

Class variables are created with the prefix ‘@@’ and are shared by all objects in a class.
Instance variables are created with the prefix ‘@’ and belong to a single object within a class.

Est-ce utile ? Oui Non Ajouter un commentaire Voir les commentaires

Question 67. Example some of the looping structures available in Ruby?

For loop, While loop, Until Loop.

Est-ce utile ? Oui Non Ajouter un commentaire Voir les commentaires

Question 68. Explain the difference between a has_one and belongs_to association in Ruby on Rails.

has_one: Indicates a direct 1:1 relationship between objects where each instance of a model contains one instance of another model.
A product has_one provider, a customer has_one order.

Est-ce utile ? Oui Non Ajouter un commentaire Voir les commentaires

Question 69. Explain a polymorphic association in Ruby on Rails.

Polymorphic associations allow a model to belong to more than one other model through a single association.

class Picture < ActiveRecord::Base

belongs_to : imageable, polymorphic: true

end

class Employee < ActiveRecord::Base

has_many : pictures, as: : imageable

end

class Product < ActiveRecord::Base

has_many : pictures, as: : imageable

end

Here, the class Picture belongs_to both Employee and Product, but does so through a single association rather than through multiple.
Be sure to know an appropriate situation to create a polymorphic association, such as creating a comment model associated with multiple other models (articles, photos, etc.). The advantage of using polymorphism here is that it allows you to create a single comment model, rather than separate models for each one (PhotoComment model, ArticleComment model, etc.)

Est-ce utile ? Oui Non Ajouter un commentaire Voir les commentaires

Question 70. What is a Proc?

Procs, short for procedures, act similar to blocks, but can be saved as variables and reused. Think of them as blocks you can call over and over again on multiple arrays.

Est-ce utile ? Oui Non Ajouter un commentaire Voir les commentaires

Les plus utiles selon les utilisateurs :