ruby 如何将新项目添加到哈希
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How to add new item to hash
提问by Иван Бишевац
I'm new to Ruby and don't know how to add new item to already existing hash. For example, first I construct hash:
我是 Ruby 新手，不知道如何向现有哈希添加新项目。例如，首先我构造哈希：
hash = {item1: 1}
after that a want to add item2 so after this I have hash like this:
之后想要添加 item2 所以在这之后我有这样的哈希：
{item1: 1, item2: 2}
I don't know what method to do on hash, could someone help me?
我不知道如何处理哈希，有人可以帮助我吗？
回答by pjumble
Create the hash:
创建哈希：
hash = {:item1 => 1}
Add a new item to it:
向其添加一个新项目：
hash[:item2] = 2
回答by Alexander
If you want to add new items from another hash - use mergemethod:
如果要从另一个哈希添加新项目 - 使用merge方法：
hash = {:item1 => 1}
another_hash = {:item2 => 2, :item3 => 3}
hash.merge(another_hash) # {:item1=>1, :item2=>2, :item3=>3}
In your specific case it could be:
在您的特定情况下，它可能是：
hash = {:item1 => 1}
hash.merge({:item2 => 2}) # {:item1=>1, :item2=>2}
but it's not wise to use it when you should to add just one element more.
但是当您应该再添加一个元素时使用它是不明智的。
Pay attention that mergewill replace the values with the existing keys:
请注意，merge将使用现有键替换值：
hash = {:item1 => 1}
hash.merge({:item1 => 2}) # {:item1=>2}
exactly like hash[:item1] = 2
一模一样 hash[:item1] = 2
Also you should pay attention that mergemethod (of course) doesn't effect the original value of hash variable - it returns a new merged hash. If you want to replace the value of the hash variable then use merge!instead:
您还应该注意该merge方法（当然）不会影响散列变量的原始值 - 它返回一个新的合并散列。如果要替换散列变量的值，请merge!改用：
hash = {:item1 => 1}
hash.merge!({:item2 => 2})
# now hash == {:item1=>1, :item2=>2}
回答by shilovk
hash.store(key, value)- Stores a key-value pair in hash.
hash.store(key, value)- 在哈希中存储键值对。
Example:
例子：
hash #=> {"a"=>9, "b"=>200, "c"=>4}
hash.store("d", 42) #=> 42
hash #=> {"a"=>9, "b"=>200, "c"=>4, "d"=>42}
回答by Niklas B.
It's as simple as:
这很简单：
irb(main):001:0> hash = {:item1 => 1}
=> {:item1=>1}
irb(main):002:0> hash[:item2] = 2
=> 2
irb(main):003:0> hash
=> {:item1=>1, :item2=>2}
回答by Connor Leech
hash[key]=value Associates the value given by value with the key given by key.
hash[key]=value 将 value 给定的值与 key 给定的键相关联。
hash[:newKey] = "newValue"
From Ruby documentation: http://www.tutorialspoint.com/ruby/ruby_hashes.htm
来自 Ruby 文档：http: //www.tutorialspoint.com/ruby/ruby_hashes.htm
回答by KrisT
hash_items = {:item => 1}
puts hash_items
#hash_items will give you {:item => 1}
hash_items.merge!({:item => 2})
puts hash_items
#hash_items will give you {:item => 1, :item => 2}
hash_items.merge({:item => 2})
puts hash_items
#hash_items will give you {:item => 1, :item => 2}, but the original variable will be the same old one.
回答by Ravi Kashyap
Create hash as:
创建哈希为：
h = Hash.new
=> {}
Now insert into hash as:
现在插入哈希为：
h = Hash["one" => 1]
