Nil as the absence of value in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign nil to the variable.

Ruby

value = [1]

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

ANone

Bnil

Cundefined

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'null' or 'None' which are from other languages.

Using 'undefined' which is not a Ruby keyword.

In Ruby, nil represents the absence of a value.

2fill in blank

medium

Complete the code to check if the variable is nil.

Ruby

if value.[1]?
  puts "Value is nil"
end

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

Anil

Bempty

Cnull

Dnone

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'empty?' which checks if a collection has no elements.

Using 'null?' or 'none?' which do not exist in Ruby.

The method nil? returns true if the object is nil.

3fill in blank

hard

Fix the error in the code to assign nil correctly.

Ruby

result = [1]

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

ANull

BNil

Cnil

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using capitalized versions like 'Nil' or 'Null'.

Using uppercase 'NULL' which is not Ruby syntax.

Ruby is case-sensitive. The correct keyword is lowercase nil.

4fill in blank

hard

Fill both blanks to create a hash with keys and nil values for missing data.

Ruby

person = { name: "Alice", age: [1], city: [2] }

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

Anil

B"unknown"

D"none"

Attempts:

3 left

💡 Hint

Common Mistakes

Using strings like 'unknown' or 'none' instead of nil.

Mixing string and nil values inconsistently.

Use nil to represent missing or unknown values in Ruby hashes.

5fill in blank

hard

Fill all three blanks to return a default value if the variable is nil.

Ruby

default = "Guest"
name = [1] || [2] if [3].nil?

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

Ainput_name

Bdefault

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Not checking for nil properly.

This code assigns default if input_name is nil.