Stop checking if it's nil in Rails

From Nested Hash

🤔 Umm,

Sometimes, I see like this code. The first row guards from the case of session[:user] == nil.

if session[:hoge]
  fuga = session[:hoge][:fuga]
  piyo = session[:hoge][:piyo]
end

But, this way is not straight forward. How we cut the first line. The logic is NOT THE BUSSINESS LOGIC!!

🦄 Clear

Hash#dig makes it simple. It checks the key-value is existed or not, and if it's not existed, dig returns nil.

It's similar of the .& method.

fuga = session.dig(:hoge,:fuga)
piyo = session.dig(:hoge,:piyo)

👍 From Object

The safe navigate operator &. (We Japanese call it alone operator. It looks so).

This picture is inversion of &

10&.to_s  # => "10"
nil&.to_s #=> nil

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🔗 Parent Note

My Rails note

n350071🇯🇵 ・ Sep 11 '19 ・ 3 min read

#rails