在Ruby on Rails中對nil v。空v。空白的簡要解釋 - A concise explanation of nil v. empty v. blank in Ruby on Rails

問題：

I find myself repeatedly looking for a clear definition of the differences of nil? 我發現本身一再尋找nil?差別的明肯定義nil? , blank? ， blank? , and empty? ， empty? in Ruby on Rails. 在Ruby on Rails中。 Here's the closest I've come: 這是我最接近的：

• blank? objects are false, empty, or a whitespace string. 對象是false，空或空白字符串。 For example, "" , " " , nil , [] , and {} are blank. 例如， "" ， " " ， nil ， []和{}爲空。

• nil? objects are instances of NilClass. 對象是NilClass的實例。

• empty? objects are class-specific, and the definition varies from class to class. 對象是特定於類的，而且定義因類而異。 A string is empty if it has no characters, and an array is empty if it contains no items. 若是字符串沒有字符，則該字符串爲空;若是字符串不包含任何項目，則該字符串爲空。

Is there anything missing, or a tighter comparison that can be made? 有什麼遺漏，或者能夠作出更嚴格的比較嗎？

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解決方案：

參考一： https://stackoom.com/question/3iKs/在Ruby-on-Rails中對nil-v-空v-空白的簡要解釋
參考二： https://oldbug.net/q/3iKs/A-concise-explanation-of-nil-v-empty-v-blank-in-Ruby-on-Rails