红宝石：从一个值对象的数组新数组 [英] Ruby: new array from one value in an array of objects

问题描述

原谅我，如果这已经被问，我找不到它。

Forgive me if this has already been asked, I couldn't find it.

我有对象的数组，如：

[<#Folder id:1, name:'Foo', display_order: 1>,
<#Folder id:1, name:'Bar', display_order: 2>,
<#Folder id:1, name:'Baz', display_order: 3>]

我想这个数组转换为数组刚的名字，如：

I'd like to convert that array into an array just of the names, like:

['Foo','Bar','Baz']

和，而我在这这将是很好，如果我可以使用相同的技术在道路上创建两个参数的数组，即名称，显示顺序将如下所示：

and, while I'm at it it would be nice if I could use the same technique down the road to create an array from two of the parameters, ie name and display order would look like:

[['Foo',1],['Bar',2],['Baz',3]]

什么是最好的Ruby之道做这种事情？

What's the best 'Ruby Way' to do this kind of thing?

谢谢！

推荐答案

这些怎么样？

# ['Foo','Bar','Baz']
array = folders.map { |f| f.name }
# This does the same, but only works on Rails or Ruby 1.8.7 and above.
array = folders.map(&:name)

# [['Foo',1],['Bar',2],['Baz',3]]
array = folders.map { |f| [f.name, f.display_order] }

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