如何创建嵌套哈希表

Question

我如何在一个哈希中创建一个嵌套的哈希，并且让嵌套的哈希有一个键来标识它？同时，对于我在嵌套哈希中创建的元素，如何给它们分配键呢？

例如：

test = Hash.new()

#create second hash with a name?? test = Hash.new("test1")??
test("test1")[1] = 1???
test("test1")[2] = 2???

#create second hash with a name/key test = Hash.new("test2")???
test("test2")[1] = 1??
test("test2")[2] = 2??

谢谢你

- paul

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欢迎来到SO。如果Joel回答了你的问题，请点击答案旁边的勾选标志将其标记为所选答案。 - pcg79

Answer 1

my_hash = { :nested_hash => { :first_key => 'Hello' } }

puts my_hash[:nested_hash][:first_key]
$ Hello

或者

my_hash = {}  

my_hash.merge!(:nested_hash => {:first_key => 'Hello' })

puts my_hash[:nested_hash][:first_key]
$ Hello

- Joel AZEMAR

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在“新”的1.9语法中，h = {car: {tires: "Michelin", engine: "Wankel"}}可以翻译为：h = {汽车: {轮胎: "米其林"，发动机: "旋转式"}}。 - Jonas Elfström

只是为了澄清，{ tires: 1 } 等同于 { :tires => 1 }，并且可以使用 hash[:tires] 检索值。只需将冒号移动到名称的末尾，并删除 => 即可。 - Kudu

Answer 2

我会选择Joel的方法，但也可以这样做：

test = Hash.new()
test['test1'] = Hash.new()
test['test1']['key'] = 'val'

- glortho

Answer 3

h1 = {'h2.1' => {'foo' => 'this', 'cool' => 'guy'}, 'h2.2' => {'bar' => '2000'} }
h1['h2.1'] # => {'foo' => 'this', 'cool' => 'guy'}
h1['h2.2'] # => {'bar' => '2000'}
h1['h2.1']['foo'] # => 'this'
h1['h2.1']['cool'] # => 'guy'
h1['h2.2']['bar'] # => '2000'

- Kudu