Rails new project generation - Practice Problems & Coding Challenges

Challenge - 5 Problems

📝 Syntax

intermediate

Correct command to create a new Rails project with PostgreSQL

Which command correctly creates a new Rails project named blog_app using PostgreSQL as the database?

A rails new blog_app --database=postgresql

B rails new blog_app -d mysql

C rails new blog_app --database=mysql

D rails new blog_app --db=postgresql

💡 Hint

Use the official Rails option to specify the database type.

The correct flag to specify the database is --database or -d followed by the database name. PostgreSQL is specified as 'postgresql'.

❓ component_behavior

intermediate

Effect of --skip-bundle option during Rails project creation

What happens when you run rails new shop_app --skip-bundle?

A The project is created but gems are not installed automatically.

B The project creation fails due to missing gems.

C The project is created and gems are installed automatically.

D The project is created without generating any files.

💡 Hint

Think about what 'bundle' means in Rails context.

The --skip-bundle option tells Rails to create the project but skip running 'bundle install' which installs gems.

❓ state_output

advanced

Number of files generated by default in a new Rails project

After running rails new forum_app with default options, how many files are generated in the project directory (approximately)?

A About 50 files

B About 100 files

C About 200 files

D About 500 files

💡 Hint

Rails generates many configuration, initializers, and default files.

A new Rails project generates roughly 200 files including config, app, bin, and test folders.

🔧 Debug

advanced

Error caused by missing Ruby version during Rails new

You run rails new api_app but get an error: Could not find Ruby version 3.1.0. What is the most likely cause?

A The command syntax is incorrect.

B Rails does not support Ruby 3.1.0.

C You need to update Rails to the latest version.

D Ruby 3.1.0 is not installed on your system.

💡 Hint

Rails requires the Ruby version specified in the Gemfile or default.

The error means your system does not have the Ruby version required by Rails or the project.

🧠 Conceptual

expert

Understanding the purpose of the Rails 'app' directory after new project generation

What is the main purpose of the app directory created by rails new?

A It stores configuration files for the Rails environment.

B It contains the core application code like models, views, and controllers.

C It holds the database schema and migration files.

D It contains the Ruby gems and dependencies.

💡 Hint

Think about where you write your app's main code.

The app directory is where Rails expects your main application code: models, views, controllers, helpers, and assets.