Pipeline operator concept in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Ruby pipeline code?

Consider the following Ruby code using the pipeline operator |>. What will be printed?

Ruby

result = 5 |> ->(x) { x * 2 } |> ->(x) { x + 3 }
puts result

A 13

B 16

C 10

D 8

💡 Hint

Remember the pipeline operator passes the result of the left expression as the argument to the right lambda.

The number 5 is first doubled to 10, then 3 is added to get 13.

❓ Predict Output

intermediate

What does this pipeline expression return?

Given this Ruby code, what is the value of output?

Ruby

output = 'hello' |> ->(s) { s.upcase } |> ->(s) { s.reverse }
puts output

A HELLO

B OLLEH

C olleh

D hello

💡 Hint

The string is first converted to uppercase, then reversed.

The string 'hello' becomes 'HELLO' after upcase, then reversed to 'OLLEH'.

🔧 Debug

advanced

Why does this pipeline code raise an error?

Look at this Ruby code using the pipeline operator. Why does it raise an error?

Ruby

value = 10 |> ->(x) { x / 0 } |> ->(x) { x + 1 }
puts value

A NoMethodError because the lambda is missing

B SyntaxError because the pipeline operator is used incorrectly

C ZeroDivisionError because dividing by zero is not allowed

D TypeError because 10 is not a valid input

💡 Hint

Think about what happens when you divide a number by zero in Ruby.

Dividing by zero causes a ZeroDivisionError at runtime.

🧠 Conceptual

advanced

What is the main benefit of using the pipeline operator in Ruby?

Choose the best explanation for why the pipeline operator |> is useful in Ruby programming.

A It allows chaining of method calls or functions in a clear, readable way by passing the result of one expression as input to the next.

B It replaces all loops and conditionals with a single operator.

C It automatically parallelizes code execution for faster performance.

D It converts all variables to strings before processing.

💡 Hint

Think about how data flows through chained operations.

The pipeline operator improves readability by making data flow explicit and linear.

📝 Syntax

expert

Which option correctly uses the pipeline operator with a method that takes multiple arguments?

Given a method def add(x, y); x + y; end, which pipeline usage is valid to add 5 and 3?

Ruby

def add(x, y)
  x + y
end

A 5 |> ->(x) { add(3, x) }

B 5 |> add(3)

C 5 |> ->(x, y) { add(x, y) }

D 5 |> ->(x) { add(x, 3) }

💡 Hint

Remember the pipeline operator passes only one argument to the right side.

Option D correctly uses a lambda to accept the pipeline input and calls add with the fixed second argument 3.