freeCodeCamp/guide/chinese/ruby/ruby-hash/index.md

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---
title: Ruby Hash
localeTitle: Ruby哈希
---
## Ruby哈希
哈希表示不同键值对的集合。它也被称为关联数组。要在Ruby中创建哈希请使用大括号并使用逗号分隔每个键值对。
```ruby
my_hash = {:key1 => "value", :key2 => "value2"}
```
您可以通过以下方式创建哈希
```ruby
my_hash = Hash.new # with empty hash
my_hash = {:key1 => "value", :key2 => "value2"} # with key's and value's defined
```
您可以使用方括号和键引用访问哈希中键的值
```ruby
my_hash[:key1] # value
my_hash[:key2] # value2
```
您可以为已定义的哈希分配新密钥和值
```ruby
my_hash[:key3] = "value3" # {:key1=>"value", :key2=>"value2", :key3=>"value3"}
```
您可以使用`length`方法检查哈希的元素数量:
```ruby
my_hash.length # 2
```
您也可以将整数创建为散列键,但语法与通常的不同
```ruby
my_hash = {1: "value"} # will raise an exception
my_hash = {1 => "value"} # will create hash with corresponding key value pair
```