Conditional assignment (||=) in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign 10 to x only if x is nil or false.

Ruby

x [1] 10

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

A+=

B=

C&&=

D||=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = assigns unconditionally.

Using &&= assigns only if variable is truthy.

Using += adds to the existing value.

The ||= operator assigns the value only if the variable is nil or false.

2fill in blank

medium

Complete the code to set default value 'guest' for username if it is nil or false.

Ruby

username [1] 'guest'

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

A&&=

B=

C||=

D+=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = overwrites the value always.

Using &&= assigns only if variable is truthy.

Using += tries to add strings.

The ||= operator sets username to 'guest' only if it is nil or false.

3fill in blank

hard

Fix the error in the code to assign 5 to count only if count is nil or false.

Ruby

count [1] 5

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

A||=

B=

C&&=

D+=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = assigns unconditionally.

Using &&= assigns only if variable is truthy.

Using += adds to the existing value.

Using ||= ensures count is assigned 5 only if it is nil or false.

4fill in blank

hard

Fill both blanks to assign 'blue' to color only if color is nil or false, and then append ' sky' to it.

Ruby

color [1] 'blue'
color [2] ' sky'

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

A||=

B+=

C=

D&&=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = instead of ||= causes unconditional assignment.

Using &&= instead of ||= won't assign if nil.

Using = instead of += won't append.

First, color ||= 'blue' assigns 'blue' if color is nil or false. Then, color += ' sky' appends ' sky' to the string.

5fill in blank

hard

Fill all three blanks to assign 0 to score if nil or false, then add 10, then assign 'done' to status if nil or false.

Ruby

score [1] 0
score [2] 10
status [3] 'done'

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

A||=

B+=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = instead of ||= causes unconditional assignment.

Using = instead of += won't add to score.

Mixing up the order of operations.

First, score ||= 0 sets score to 0 if nil or false. Then, score += 10 adds 10. Finally, status ||= 'done' sets status if nil or false.