Ruby Errors

Ruby uses exceptions to report errors and other information when something in the program has gone wrong.

If an error has occurred, the Ruby program will end. For example:

puts 2 / 0

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This will result in:

Traceback (most recent call last):
        1: from errors_in_ruby.rb:1:in `<main>'
errors_in_ruby.rb:1:in `/': divided by 0 (ZeroDivisionError)

Some common errors are:

• RuntimeError
• StandardError
• NoMethodError
• IOError
• TypeError
• ArgumentError

Rescuing Errors

Use the rescue keyword in a begin...end block to catch errors and report messages. The error can be as general as StandardError or as specific as ZeroDivisionError:

begin
  puts 2 / 0
rescue ZeroDivisionError
  puts "Can't divide by 0"
end

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