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三項演算子で書いた式の戻り値を、配列の要素として追加しようとしたが、<<メソッドを使っていたために少し詰まった

経緯

  • 配列に要素を追加するときは、 << メソッドを使っていたのですが、表題の件で2~3分詰まったので投稿します。

サンプルコード

  • 一つ目の要素追加では obj.nil? の結果が配列に追加されてしまいます。
  • 三項演算子で書いた式の戻り値を追加したい場合は、二つ目のように()で囲むか、三つ目のように push メソッドを使う必要があります。
sample001.rb
obj = nil
array = []

array << obj.nil? ? 'nnn' : 'aaa'
array << (obj.nil? ? 'nnn' : 'aaa')
array.push obj.nil? ? 'nnn' : 'aaa'

puts array

実行結果

$ ruby sample001.rb
true
nnn
nnn

参考

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