Debugging Techniques

Finding and fixing errors is an essential skill in programming.

In this lesson, you will learn how to debug Ruby code using puts, pry, and byebug.

Using puts for Debugging

Use puts to print variable values and track program flow.

name = 'Alice'
puts "Debug: name is #{name}"

Using inspect

Use inspect to view detailed object properties.

arr = [1, 2, 3]
puts arr.inspect

Using raise for Debugging

Use raise to stop execution and display a message.

x = 10
raise 'Unexpected value' if x > 5

Using pry

pry is an interactive debugger for Ruby.

Install it using gem install pry and require it in your code.

require 'pry'
def test_method
  x = 10
  binding.pry # Debugger stops here
  puts x
end
test_method

Using byebug

byebug is another debugging tool for Ruby.

Install it using gem install byebug and require it in your code.

require 'byebug'
def test_method
  x = 10
  byebug # Debugger stops here
  puts x
end
test_method

Reading Error Messages

Error messages provide clues about what went wrong and where.

begin
  num = Integer('abc')
rescue ArgumentError => e
  puts "Error message: #{e.message}"
end

Comparing puts and inspect

puts is best for simple output, while inspect is useful for debugging complex objects.

hash = { name: 'Alice', age: 25 }
puts hash
puts hash.inspect

Congratulations!

You have learned various debugging techniques in Ruby.

Next, you will explore the basics of Ruby on Rails.