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Ruby | Delete only the first element in the array (get everything afte

2019/04/16に公開

Solution

drop it.

 ['A','B','C','D','E'].drop(1) # => ["B", "C", "D", "E"]

If you shift the array, the extracted element will be the return value. It is not a remaining element.

 ['A','B','C','D','E'].shift => "A"

shift is destructive in the first place. So there is no shift!

 ['A','B','C','D','E'].shift! # => NoMethodError: undefined method `shift!' for ["A", "B", "C", "D", "E"]:Array

I can get the value I want. I have to write three lines.

 alphabets = ['A','B','C','D','E'] alphabets.shift alphabets # => ["B", "C", "D", "E"]

So far, I have been asking [1..-1] for arrays.

 ['A','B','C','D','E'][1..-1] # => ["B", "C", "D", "E"]

1 means the second of the array. (Not 2 ) -1 means the end of the array.

何か質問、悩み事、相談などあればLINEオープンチャットもご利用ください。

2019-04-16