Format validation in Ruby on Rails - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to validate that the email attribute has the correct format.

Ruby on Rails

validates :email, format: { with: [1] }

Drag options to blanks, or click blank then click option'

A/\A[^@\s]+@[^@\s]+\z/

B/[a-z]+/

C/\s+/

D/\d+/

Attempts:

3 left

💡 Hint

Common Mistakes

Using a regex that matches only letters or digits.

Not anchoring the regex to start and end of string.

The regex /\A[^@\s]+@[^@\s]+\z/ ensures the email has a basic valid format with one '@' and no spaces.

2fill in blank

medium

Complete the code to add a custom error message for invalid email format.

Ruby on Rails

validates :email, format: { with: /\A[^@\s]+@[^@\s]+\z/, message: [1] }

Drag options to blanks, or click blank then click option'

A"is invalid"

B"must be unique"

C"is too short"

D"can't be blank"

Attempts:

3 left

💡 Hint

Common Mistakes

Using messages unrelated to format validation.

Forgetting to put the message in quotes.

The message "is invalid" clearly tells the user the email format is wrong.

3fill in blank

hard

Fix the error in the validation code to correctly validate a username with only letters and numbers.

Ruby on Rails

validates :username, format: { with: [1] }

Drag options to blanks, or click blank then click option'

A/[a-z]+/

B/[a-zA-Z0-9]/

C/\w+/

D/\A[a-zA-Z0-9]+\z/

Attempts:

3 left

💡 Hint

Common Mistakes

Using regex without anchors, allowing invalid characters.

Using \w+ which includes underscores.

The regex /\A[a-zA-Z0-9]+\z/ ensures the username contains only letters and numbers from start to end.

4fill in blank

hard

Fill both blanks to validate a phone number that must be exactly 10 digits.

Ruby on Rails

validates :phone, format: { with: [1], message: [2] }

Drag options to blanks, or click blank then click option'

A/\A\d{10}\z/

B"must be 10 digits"

C"invalid phone number"

D/\d+/

Attempts:

3 left

💡 Hint

Common Mistakes

Using a regex that matches any number of digits.

Using a vague or unrelated error message.

The regex /\A\d{10}\z/ matches exactly 10 digits, and the message clearly states the requirement.

5fill in blank

hard

Fill all three blanks to validate a password with at least 8 characters, including letters and numbers.

Ruby on Rails

validates :password, format: { with: [1], message: [2], allow_blank: [3] }

Drag options to blanks, or click blank then click option'

A/\A(?=.*[a-zA-Z])(?=.*\d).{8,}\z/

B"must include letters and numbers and be at least 8 characters"

Cfalse

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using a regex that does not check for both letters and digits.

Setting allow_blank to true, allowing empty passwords.

The regex ensures at least one letter and one digit with minimum length 8. The message explains the rule. allow_blank: false means password cannot be empty.