Range operators (.. and ...) in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of inclusive range with .. operator

What is the output of this Ruby code?

range = (1..5).to_a
puts range.inspect

Ruby

range = (1..5).to_a
puts range.inspect

A [1, 2, 3, 4, 5, 6]

B [1, 2, 3, 4]

C [1, 2, 3, 4, 5]

D SyntaxError

💡 Hint

The .. operator creates a range that includes the last number.

The .. operator creates an inclusive range, so 5 is included in the array.

❓ Predict Output

intermediate

Output of exclusive range with ... operator

What is the output of this Ruby code?

range = (1...5).to_a
puts range.inspect

Ruby

range = (1...5).to_a
puts range.inspect

A RuntimeError

B [1, 2, 3, 4, 5]

C [1, 2, 3]

D [1, 2, 3, 4]

💡 Hint

The ... operator excludes the last number from the range.

The ... operator creates an exclusive range, so 5 is not included in the array.

🧠 Conceptual

advanced

Difference between .. and ... in Ruby ranges

Which statement correctly describes the difference between the .. and ... range operators in Ruby?

A The .. operator creates an exclusive range excluding the end value; the ... operator creates an inclusive range including the end value.

B The .. operator creates an inclusive range including the end value; the ... operator creates an exclusive range excluding the end value.

C Both .. and ... create inclusive ranges including the end value.

D Both .. and ... create exclusive ranges excluding the end value.

💡 Hint

Think about whether the last number is included or not.

The .. operator includes the end value in the range, while the ... operator excludes it.

❓ Predict Output

advanced

Output of range with characters using ... operator

What is the output of this Ruby code?

range = ('a'...'d').to_a
puts range.inspect

Ruby

range = ('a'...'d').to_a
puts range.inspect

A ["a", "b", "c"]

B ["a", "b"]

C ["a", "b", "c", "d"]

D TypeError

💡 Hint

The ... operator excludes the end character.

The ... operator excludes 'd', so the array contains 'a', 'b', and 'c'.

❓ Predict Output

expert

Number of elements in a range with floating point numbers

What happens when you try to convert this range to an array?

range = (1.0..5.0).to_a
puts range.inspect

Ruby

range = (1.0..5.0).to_a
puts range.inspect

A NoMethodError: undefined method `to_a' for 1.0..5.0:Range

B [1.0, 2.0, 3.0, 4.0, 5.0]

C [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, ...]

D TypeError: can't iterate over Float range

💡 Hint

Ranges with floats do not support to_a method.

Ruby Range with floats does not support to_a because it cannot iterate over floats by default.