Array slicing and ranges in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the first three elements of the array.

Ruby

arr = [10, 20, 30, 40, 50]
slice = arr[[1]]

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

A1..3

B0..2

C2..4

D3..5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a range starting at 1 misses the first element.

Using an exclusive range (0...2) only gets two elements.

The range 0..2 selects elements at indexes 0, 1, and 2, which are the first three elements.

2fill in blank

medium

Complete the code to get the last two elements of the array.

Ruby

arr = [5, 10, 15, 20, 25]
slice = arr[[1]]

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

A-2..-1

B-3..-1

C3..4

D2..3

Attempts:

3 left

💡 Hint

Common Mistakes

Using -3..-1 gets three elements instead of two.

Using positive indexes may be less clear for the last elements.

The range -2..-1 selects the last two elements of the array using negative indexes.

3fill in blank

hard

Fix the error in the code to slice the array from index 1 to 3 inclusive.

Ruby

arr = [2, 4, 6, 8, 10]
slice = arr[[1]]

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

A1...3

B0..2

C2..4

D1..3

Attempts:

3 left

💡 Hint

Common Mistakes

Using a triple dot range excludes the last element.

Using wrong indexes results in wrong slice.

The range 1..3 includes indexes 1, 2, and 3. The range 1...3 excludes index 3.

4fill in blank

hard

Fill both blanks to create a slice from the second to the fourth element (inclusive).

Ruby

arr = ['a', 'b', 'c', 'd', 'e']
slice = arr[[1]..[2]]

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

A1

B2

C3

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2 as start misses the second element.

Using 4 as end includes the fifth element.

Indexes 1 to 3 correspond to the second, third, and fourth elements.

5fill in blank

hard

Fill all three blanks to create a slice from the third element to the last element.

Ruby

arr = [100, 200, 300, 400, 500]
slice = arr[[1]..[2]]
puts slice[[3]]

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

A2

B4

C0

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 as start misses the third element.

Using 3 as end excludes the last element.

Using 2 as slice index causes wrong output.

The slice from index 2 to 4 includes elements 300, 400, 500. The first element of the slice is at index 0.