Exception Handling in Ruby: A Beginner's Guide

Introduction to Exception Handling

Exception handling is a crucial aspect of programming that allows you to gracefully handle errors and unexpected situations in your code. In Ruby, exceptions are objects that represent errors. Exception handling enables you to write code that can recover from errors and provide a better user experience. In this guide, we'll explore the basics of exception handling in Ruby with examples.

Types of Exceptions

Ruby has a wide variety of built-in exceptions. Here are some common types of exceptions:

begin
  # Code that may raise an exception
  result = 10 / 0
rescue ZeroDivisionError
  puts "Division by zero error!"
end
    

In this example, a ZeroDivisionError exception is raised because we are attempting to divide by zero. The rescue block catches the exception and provides an error message.

Handling Exceptions

You can use the begin and rescue blocks to handle exceptions and gracefully recover from errors. Here's an example:

begin
  result = 10 / 0
rescue ZeroDivisionError
  puts "Division by zero error! Setting result to 0."
  result = 0
end
puts "Result: #{result}"
    

In this example, the rescue block handles the ZeroDivisionError by setting the result to 0 instead of crashing the program.

Raising Exceptions

You can also raise exceptions explicitly using the raise keyword. Here's an example:

def check_age(age)
  if age < 18
    raise ArgumentError, "You must be at least 18 years old."
  end
end
begin
  check_age(15)
rescue ArgumentError => e
  puts "Error: #{e.message}"
end
    

In this example, the check_age method raises an ArgumentError if the age is less than 18. The rescue block catches the exception and displays the error message.

Conclusion

Exception handling is a vital skill for writing robust and reliable Ruby programs. It allows you to manage errors, handle unexpected situations, and ensure a better user experience. By understanding the basics of exception handling, you can write code that gracefully recovers from errors.

Practice exception handling in your Ruby programs to become a proficient Ruby developer. For more information, refer to the official Ruby documentation.

Happy coding!