Dynamic typing vs strong typing in Ruby - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Ruby code with dynamic typing?

Consider this Ruby code snippet. What will it print?

Ruby

x = 10
x = "hello"
puts x

A nil

B 10

C hello

D TypeError

💡 Hint

In Ruby, variables can hold any type and can change type.

Ruby is dynamically typed, so the variable x can hold an integer first, then a string. The last value assigned is printed.

❓ Predict Output

intermediate

What error does this Ruby code raise due to strong typing?

What error will this Ruby code produce?

Ruby

a = 5
b = "3"
puts a + b

A 8

B TypeError

C ArgumentError

D NoMethodError

💡 Hint

Ruby does not automatically convert between strings and numbers for addition.

Ruby is strongly typed, so adding an integer and a string without conversion causes a TypeError.

🧠 Conceptual

advanced

Which statement best describes Ruby's typing system?

Choose the statement that correctly describes Ruby's typing.

A Ruby is dynamically typed and strongly typed.

B Ruby is statically typed and weakly typed.

C Ruby is statically typed and strongly typed.

D Ruby is dynamically typed and weakly typed.

💡 Hint

Think about when types are checked and if implicit conversions happen.

Ruby checks types at runtime (dynamic typing) and does not allow implicit type coercion in operations (strong typing).

❓ Predict Output

advanced

What is the output of this Ruby code mixing types?

What will this Ruby code print?

Ruby

def add(x, y)
  x + y
end

puts add(2, 3)
puts add("2", "3")
puts add(2, "3")

A

5
23
TypeError

B

5
23
5

C

TypeError
TypeError
TypeError

D

5
TypeError
TypeError

💡 Hint

Consider how Ruby handles addition for integers and strings, and what happens when types differ.

Adding integers works (5). Adding strings concatenates ("23"). Adding integer and string causes TypeError.

🧠 Conceptual

expert

Why does Ruby raise a TypeError when adding integer and string?

Choose the best explanation for why Ruby raises a TypeError when adding an integer and a string.

A Because Ruby is dynamically typed and allows any operation between types.

B Because Ruby automatically converts strings to integers but fails here due to syntax.

C Because Ruby is statically typed and checks types at compile time.

D Because Ruby is strongly typed and does not perform implicit type conversion between incompatible types.

💡 Hint

Think about how Ruby treats types during operations and if it converts types automatically.

Ruby's strong typing means it forbids operations between incompatible types without explicit conversion, causing TypeError.