How to avoid NoMethodError for nil elements when accessing nested hashes? [duplicate]

Answer 1

You can simply use unless to test this:

irb(main):001:0> def checker(val)
irb(main):002:1>   unless val.nil?
irb(main):003:2>     puts 'working on the railroad'
irb(main):004:2>     end
irb(main):005:1>   end
=> nil
irb(main):006:0> x = nil
=> nil
irb(main):007:0> checker(x)
=> nil
irb(main):008:0> y = 1
=> 1
irb(main):009:0> checker(y)
working on the railroad
=> nil
irb(main):010:0>