我有一系列哈希,我想写一个通用的检查器,所以我想传入要检查的键的名称.散列是使用带冒号前缀(符号)的键定义的.我无法弄清楚如何正确使用变量作为键.即使密钥存在于散列中,使用变量访问它也会导致nil.如何通过变量访问哈希键？也许另一种要问的方法是,如何将变量强制转换为符号？
在IRB中,我这样做：
>> family = { 'husband' => "Homer",'wife' => "Marge" }
=> {"husband"=>"Homer","wife"=>"Marge"}
>> somevar = "husband"
=> "husband"
>> family[somevar]
=> "Homer"
>> another_family = { :husband => "Fred",:wife => "Wilma" }
=> {:husband=>"Fred",:wife=>"Wilma"}
>> another_family[somevar]
=> nil
>>
解决方法
您想先将字符串转换为符号：
another_family[somevar.to_sym]
如果您不想担心散列是符号还是字符串,只需将其转换为符号键即可
见：How do I convert a Ruby hash so that all of its keys are symbols?