在Ruby on Rails中对nil v。空v。空白的简要解释 - A concise explanation of nil v. empty v. blank in Ruby on Rails

问题：

I find myself repeatedly looking for a clear definition of the differences of nil? 我发现本身一再寻找nil?差别的明肯定义nil? , blank? ， blank? , and empty? ， empty? in Ruby on Rails. 在Ruby on Rails中。 Here's the closest I've come: 这是我最接近的：

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

• nil? objects are instances of NilClass. 对象是NilClass的实例。

• empty? objects are class-specific, and the definition varies from class to class. 对象是特定于类的，而且定义因类而异。 A string is empty if it has no characters, and an array is empty if it contains no items. 若是字符串没有字符，则该字符串为空;若是字符串不包含任何项目，则该字符串为空。

Is there anything missing, or a tighter comparison that can be made? 有什么遗漏，或者能够作出更严格的比较吗？

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解决方案：

参考一： https://stackoom.com/question/3iKs/在Ruby-on-Rails中对nil-v-空v-空白的简要解释
参考二： https://oldbug.net/q/3iKs/A-concise-explanation-of-nil-v-empty-v-blank-in-Ruby-on-Rails