String freezing for immutability in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to freeze the string so it cannot be changed.

Ruby

name = "Ruby".[1]

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

Aupcase

Bfreeze

Creverse

Dcapitalize

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like upcase or reverse which change the string but do not freeze it.

Using freeze on a string makes it immutable, so it cannot be changed later.

2fill in blank

medium

Complete the code to check if the string is frozen.

Ruby

str = "hello".freeze
puts str.[1]

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

Afreeze?

Bfrozen

Cfrozen?

Dis_frozen

Attempts:

3 left

💡 Hint

Common Mistakes

Using freeze instead of frozen? to check.

The method frozen? returns true if the string is frozen (immutable).

3fill in blank

hard

Complete the code to append '!' to the greeting.

Ruby

greeting = "Hi"
greeting.[1]("!")

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

Aconcat

Bupcase!

Cfreeze # Then try to modify

Dreplace

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to modify a frozen string causes error.

Using freeze before modification causes error.

concat("!") appends "!" to the string in place. This would raise a FrozenError if the string was frozen.

4fill in blank

hard

Fill both blanks to create a frozen string and check if it is frozen.

Ruby

word = "immutable".[1]
puts word.[2]

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

Afreeze

Bupcase

Cfrozen?

Dreverse

Attempts:

3 left

💡 Hint

Common Mistakes

Checking frozen? before freezing the string.

Using methods like upcase or reverse instead of freeze.

First, freeze the string to make it immutable. Then check if it is frozen using frozen?.

5fill in blank

hard

Fill all three blanks to create a frozen string, check if frozen, and try to modify it safely.

Ruby

text = "safe".[1]
if text.[2]
  puts "Cannot modify frozen string"
else
  text.[3]("!")
end

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

Afreeze

Bfrozen?

Cconcat

Dreplace

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to modify a frozen string without checking.

Using wrong methods to modify or check.

Freeze the string first. Check if it is frozen with frozen?. If not frozen, modify it with concat. This avoids errors.