Programming Ruby 3.3

Catch and Throw

The method catch executes its associated block:

catch ( object ) do     code... end

The method throw interrupts the normal processing of statements:

throw( object <, obj> )

When a throw is executed, Ruby searches up the call stack for the first catch block with a matching object. If it’s found, the search stops, and execution resumes past the end of the catch’s block. If the throw is passed a second parameter, that value is returned as the value of the catch. Ruby honors the ensure clauses of any block expressions it traverses while looking for a corresponding catch.

If no catch block matches the throw, Ruby raises an ArgumentError exception at the location of the throw.