Debugging with pry and byebug in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a debugging session using pry.

Ruby

require 'pry'

x = 10
binding.[1]
puts x

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

Astart

Bdebug

Cpry

Dsession

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'binding.start' instead of 'binding.pry'.

Forgetting to require 'pry' at the top.

To start a debugging session with pry, use binding.pry.

2fill in blank

medium

Complete the code to start a debugging session using byebug.

Ruby

require 'byebug'

x = 5
[1]
puts x

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

Adebugger

Bbinding.byebug

Cstart_debug

Dbyebug

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'binding.byebug' which is not correct syntax.

Forgetting to require 'byebug' at the top.

To start a debugging session with byebug, just call byebug where you want to pause.

3fill in blank

hard

Fix the error in the code to correctly start a pry debugging session.

Ruby

require 'pry'

x = 7
binding.[1]()
puts x

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

Apry

Bstart

Cdebug

Dsession

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses with a wrong method name.

Using 'binding.debug' which does not exist.

The correct method to call is binding.pry. It can be called with or without parentheses.

4fill in blank

hard

Fill both blanks to start a byebug session and assign a variable.

Ruby

require 'byebug'

[1] = 20
[2]
puts value

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

Avalue

Bbyebug

Cval

Ddebugger

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'value' as variable but printing 'val'.

Calling 'debugger' instead of 'byebug'.

Assign the number 20 to val and call byebug to start debugging.

5fill in blank

hard

Fill all three blanks to start a pry session, assign a variable, and print it.

Ruby

require 'pry'

[1] = 15
binding.[2]
puts [3]

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

Anum

Bpry

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatch between variable name and printed variable.

Using wrong method name after binding.

Assign 15 to num, start pry with binding.pry, and print num.

Practice

1. What is the main purpose of using binding.pry or byebug in Ruby code?

easy

A. To pause the program and inspect variables at a specific point

B. To speed up the execution of the program

C. To automatically fix syntax errors

D. To compile Ruby code into machine code

Solution

1. Step 1: Understand the role of debugging tools

   Both binding.pry and byebug are used to pause program execution.

2. Step 2: Inspect variables and program state

   When paused, you can check variable values and program flow to find issues.

3. Final Answer:

   To pause the program and inspect variables at a specific point -> Option A

4. Quick Check:

   Debugging tools pause and inspect = A [OK]

Hint: They pause code to check variables and flow [OK]

Common Mistakes:

• Thinking they speed up code
• Believing they fix errors automatically
• Confusing with code compilation

2. Which of the following is the correct way to insert a breakpoint using Pry in Ruby code?

easy

A. debug.pry

B. breakpoint.pry

C. pry.binding

D. binding.pry

Solution

1. Step 1: Recall Pry syntax for breakpoints

   The correct syntax to pause execution with Pry is binding.pry.

2. Step 2: Check other options for correctness

   Other options like breakpoint.pry, pry.binding, and debug.pry are invalid method calls.

3. Final Answer:

   binding.pry -> Option D

4. Quick Check:

   Correct Pry breakpoint syntax = D [OK]

Hint: Use exactly 'binding.pry' to pause with Pry [OK]

Common Mistakes:

• Swapping method and object order
• Using non-existent methods
• Forgetting to require 'pry'

3. What will be the output when running this Ruby code with byebug inserted?

def add(a, b)
  byebug
  a + b
end

puts add(2, 3)

medium

A. 5

B. byebug error

C. nil

D. SyntaxError

Solution

1. Step 1: Understand what byebug does

   It pauses execution allowing inspection but does not change the return value.

2. Step 2: Trace the function call and output

   The method add(2, 3) returns 5, which is printed by puts.

3. Final Answer:

   5 -> Option A

4. Quick Check:

   byebug pauses but output is 5 [OK]

Hint: byebug pauses but returns normal output [OK]

Common Mistakes:

• Expecting byebug to change output
• Thinking byebug causes errors
• Confusing pause with program stop

4. You inserted binding.pry in your Ruby code, but when you run it, the program does not pause. What is the most likely reason?

medium

A. You used byebug instead of binding.pry

B. You forgot to require the 'pry' gem in your code

C. The Ruby version does not support debugging

D. You placed binding.pry after the return statement

Solution

1. Step 1: Check if 'pry' gem is loaded

   Without require 'pry', binding.pry is undefined and won't pause.

2. Step 2: Verify placement and usage

   Using binding.pry correctly requires the gem loaded; placing after return stops execution before breakpoint.

3. Final Answer:

   You forgot to require the 'pry' gem in your code -> Option B

4. Quick Check:

   Missing require 'pry' stops pause [OK]

Hint: Always require 'pry' before using binding.pry [OK]

Common Mistakes:

• Not requiring the gem
• Placing breakpoint after return
• Confusing pry with byebug usage

5. You want to debug a method that processes a list of numbers and stops only when a number is negative. Which debugging tool and approach is best to use?

hard

A. Use puts statements to print all numbers

B. Insert byebug at the start of the method without any condition

C. Insert binding.pry inside the loop with a condition to pause only if the number is negative

D. Run the program without breakpoints and guess the error

Solution

1. Step 1: Understand conditional breakpoints

   Using binding.pry with a condition lets you pause only when needed, saving time.

2. Step 2: Compare other options

   Using byebug without condition pauses every time, puts is less interactive, guessing is ineffective.

3. Final Answer:

   Insert binding.pry inside the loop with a condition to pause only if the number is negative -> Option C

4. Quick Check:

   Conditional breakpoint with binding.pry = A [OK]

Hint: Use conditional binding.pry to pause only on negative numbers [OK]

Common Mistakes:

• Pausing unconditionally causing many stops
• Relying only on print statements
• Ignoring debugging tools