Which exceptions do you catch when you don't specify an exception class in ruby?

Question

Which exceptions are you catching when you don't specify an exception class like this:

begin
  # do something
rescue
  puts "Exception!"
end

Answer 1

According to my copy of Programming Ruby 1.9,

A rescue clause with no parameter is treated as if it had a parameter of StandardError.

And here's the documentation from ruby-doc.org:

By default, rescue only intercepts StandardError and its descendants, but you can specify which exceptions you want handled, as arguments. (This technique does not work when rescue is in statement-modifier position.)

The Why Not Wiki has the Exception hierarchy available if you need to reference it.

As a quick reference, the Exception classes that are not derived from StandardError are:

• fatal
• NoMemoryError
• ScriptError
• SignalException
• SystemExit
• SystemStackError