Ruby 1.9 hash with a dash in a key

戏子无情 提交于 2019-11-26 22:56:41

问题


In ruby 1.9 is there a way to define this hash with the new syntax?

irb> { a:  2 }
=> {:a=>2}

irb> { a-b:  2 }
SyntaxError: (irb):5: syntax error, unexpected tLABEL
{ a-b:  2 }
      ^

with the old one, it's working:

irb> { :"a-b" =>  2 }
=> {:"a-b"=>2}

回答1:


You also can use next syntax

{a: 1, b: 2, 'c-c': 3, d: 4}



回答2:


There are some legitimate symbols that cannot be used with the new syntax. I cannot find a reference, but it appears that a symbol name matching /^[a-zA-Z_][a-zA-Z_0-9]*[!?]?$/ is allowed with the new syntax. The last character may be the special character "!" or "?".

For any symbol that does not meet these restrictions, you have to use the Ruby 1.8 syntax, :'my-symbol-name'




回答3:


To use dashes with the new syntax:

<%= link_to "Link", link_path, {data: {something: 'value1', somethingelse: 'value2'}} %>

This will generate:

<a href="/link" data-something='value1' data-somethingelse='value2'>Link</a>

This might not exactly be your particular use case, but I found this post while trying to find an answer myself so I thought I'd share my findings.




回答4:


You can combine the old and new syntax:

{a: 1, b: 2, :'c-c' => 3, d: 4}


来源:https://stackoverflow.com/questions/2134702/ruby-1-9-hash-with-a-dash-in-a-key

易学教程内所有资源均来自网络或用户发布的内容,如有违反法律规定的内容欢迎反馈
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!