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Exceptions in Ruby - throwing, catching and using

It's far better to use exceptions to trap run time irregularities than to try to forecast all possible errors, as exceptions form a sort of safety net. From today's Ruby Course, [here] is an example where the user is prompted to enter an integer, and I deliberately use the Integer function rather than to_i to extract that number so that I can catch incorrect entries through an exception (Integer throws exceptions, but to_i just returns a 0).

A further example - [here] - shows how exceptions can be caught in methods or thorn up to parents, and how methods can even raise their own exceptions. If you're writing methods, it's sensible to throw exceptions up as it forces the person using you code to take into account situations where no value is to be returned.


(written 2016-05-17)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
R111 - Ruby - Exceptions.
  [4008] Reading and checking user inputs - first lessons - Ruby - (2013-02-17)
  [3435] Sorta sorting a hash, and what if an exception is NOT thrown - Ruby - (2011-09-12)
  [3433] Exceptions - a fail-safe way of trapping things that may go wrong - (2011-09-11)
  [3260] Ruby - a training example that puts many language elements together to demonstrate the whole - (2011-04-23)
  [3177] Insurance against any errors - Volcanoes and Python - (2011-02-19)
  [2622] Handling unusual and error conditions - exceptions - (2010-02-03)
  [2621] Ruby collections and strings - some new examples - (2010-02-03)
  [2620] Direct access to object variable (attributes) in Ruby - (2010-02-02)
  [2615] String to number conversion with error trapping in Ruby - (2010-02-01)
  [1875] What are exceptions - Python based answer - (2008-11-08)


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