Ruby Oneline Rescue

Question

I recently learned that you can use rescue on a line of code in case something goes wrong on that line (see http://www.rubyinside.com/21-ruby-tricks-902.html Tip #2

Answer 1

Reads good! But it will hit your performance. In my experience rescue is much slower when triggered and slightly slower when it's not. In all cases the if is faster. Other thing to consider, is that exceptions shouldn't be expected and you kind of are with this code. Having a hash so deeply nested might be a good smell that a refactoring is nede

Answer 2

This specific example can now be achieved with Ruby 2.3's dig method.

name = obj.dig 'key', 'key2', 'name'

This will safely access obj['key']['key2']['name'], returning nil if any step fails.

(In general, it's usually advised to use exceptions only for real, unanticipated, errors, though it's understandable in an example like this if the syntax makes it cumbersome.)