红宝石：通过哈希

Question

数组生成散列的哈希

我有以下

friends = [{ name: "Jack", attr1:"def", attr2:"def" }, { name: "Jill", attr1:"def", attr2:"def" }] 

我想上述表示转换成哈希散列这样

friends = { "Jack" => { attr1: "def", attr2:"def" }, "Jill" => { attr1: "def", attr2: "def" } } 

任何优雅的方式在Ruby中这样做？

Answer 1

Hash[friends.map { |f| _f = f.dup; [_f.delete(:name), _f] }] 
# => {"Jack"=>{:attr1=>"def", :attr2=>"def"}, "Jill"=>{:attr1=>"def", :attr2=>"def"}} 

Answer 2

当你想一个数组转换为另一种，用collect：

friends = Hash[ 
    friends.collect do |f| 
    _f = f.dup 
    name = _f.delete(:name) 
    [ name, _f ] 
    end 
] 

您可以创建一个新的哈希容易使用Hash[]，并为其提供了一系列的键/值对数组它。在这种情况下，name字段将从每个字段中删除。

Answer 3

friends.each_with_object({}) do |f, o| 
    f = f.dup 
    o[f.delete :name] = f 
end 

Answer 4

hash = {} 
friends.each{|h| hash[h.delete(:name)] = h } 
# => {"Jack"=>{:attr1=>"def", :attr2=>"def"}, "Jill"=>{:attr1=>"def", :attr2=>"def"}} 

Answer 5

如果我们理解“优雅”来写通过利用可重用的抽象简洁的代码的方式，我会写：

require 'active_support/core_ext/hash' 
require 'facets/hash' 
friends.mash { |f| [f[:name], f.except(:name)] } 

无需添加gem依赖这两个相当大型图书馆，你可以随时在你的扩展库中实现个别方法。