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我想初始化一个常量,如果它不存在,如果已经存在,然后使用它。我尝试了下面的警告。如何处理初始化常量?
User = User || Struct.new(:name) #NameError: uninitialized constant User
User = Struct.new(:name) || User #works (1st time)
但这句话会遇到多次,这种情况发生时,我得到
User = Struct.new(:name) || User
#warning: already initialized constant User
#warning: previous definition of User was here
如何处理这种情况?
啊哈,我觉得'a || = b'等于'a = a || b' – Bala
@Bala不,它不是..我明白, –