54 lines
1.4 KiB
Markdown
54 lines
1.4 KiB
Markdown
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---
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title: Ruby Hashes
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localeTitle: Ruby Hashes
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---
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## Ruby Hashes
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哈希是键和值的集合。它类似于其他语言中通常所说的字典。在Ruby中，散列类似于[数组](https://raw.githubusercontent.com/freeCodeCamp/guides/master/src/pages/ruby/ruby-arrays/index.md) ，但不是简单地存储它存储键值对的值。
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```ruby
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array = ["value"]
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hash = { "key" => "value" }
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```
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创建新哈希有几种不同的方法：
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```ruby
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hash1 = {a: 100, b: "200"}
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hash2 = Hash.new
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hash3 = Hash.new(0) # with default value set to 0
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```
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然后，程序员可以使用其键而不是索引来访问哈希值。
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```ruby
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array[0] # => "value"
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hash["key"] # => "value"
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```
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通过这种方式，哈希的行为更像是字典，您可以通过其键查找值。
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```ruby
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dictionary = { "Aardvark" => "a large, nocturnal, burrowing mammal",
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"Zyzzyva" => "a genus of tropical weevils" }
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dictionary["Aardvark"] # => "a large, nocturnal, burrowing mammal"
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dictionary["Zyzzyva"] # => "a genus of tropical weevils"
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```
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您还可以使用[符号](#)作为键创建哈希。
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```ruby
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hash = { :symbol => "value" }
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hash[:symbol] # => "value"
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```
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此外，如果您的所有键都是[符号](#) ，则可以使用此备用格式编写哈希值，但您可以以相同的方式访问它：
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```ruby
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hash = { symbol: "value" }
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hash[:symbol] # => "value"
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```
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#### 更多信息：
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[Ruby哈希文档](https://ruby-doc.org/core-2.4.2/Hash.html)
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