blocks|key|1685624|text|不，我不认为你可以附加键/值对。据我所知，唯一最接近的方法是使用store方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1685625|h+=+{}
h.store("key",+"value")|code-block|syntax|javascript|1685626|entityMap^0|W|5|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

No, I don't think you can append key/value pairs. The only thing closest that I am aware of is using the <code>store</code> method:

<pre><code>h = {}
h.store("key", "value")
</code></pre>

blocks|key|1899244|text|也许你想要Hash#merge？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1899245|1.9.3p194+:015+>+h={}
+=>+{}+
1.9.3p194+:016+>+h.merge(:key+=>+'bar')
+=>+{:key=>"bar"}+
1.9.3p194+:017+>+|code-block|syntax|javascript|1899246|如果要就地更改数组，请使用merge!|offset|length|style|CODE|1899247|1.9.3p194+:016+>+h.merge!(:key+=>+'bar')
+=>+{:key=>"bar"}+|1899248|entityMap^0|0|0|D|6|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Perhaps you want Hash#merge ?

<pre><code>1.9.3p194 :015 &gt; h={}
 =&gt; {} 
1.9.3p194 :016 &gt; h.merge(:key =&gt; 'bar')
 =&gt; {:key=&gt;"bar"} 
1.9.3p194 :017 &gt; 
</code></pre>

If you want to change the array in place use <code>merge!</code>

<pre><code>1.9.3p194 :016 &gt; h.merge!(:key =&gt; 'bar')
 =&gt; {:key=&gt;"bar"} 
</code></pre>

blocks|key|1899256|text|这就是merge!。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1899257|h+=+{}
h.merge!(key:+"bar")
#+=>+{:key=>"bar"}|code-block|syntax|javascript|1899258|entityMap|0|LINK|mutability|MUTABLE|url|http://ruby-doc.org/core-2.2.0/Hash.html#method-i-merge-21^0|3|6|3|6|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@$9|V|A|W|1|X]]|E|$]]|$1|F|3|G|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

There is <a href="http://ruby-doc.org/core-2.2.0/Hash.html#method-i-merge-21" rel="noreferrer"><code>merge!</code></a>.

<pre><code>h = {}
h.merge!(key: "bar")
# =&gt; {:key=&gt;"bar"}
</code></pre>

blocks|key|1685699|text|由于哈希本身并不是有序的，所以没有附加的概念。但是，从1.9开始，Ruby散列保持了插入顺序。下面是添加新的键/值对的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1685700|最简单的解决方案是|1685701|h[:key]+=+"bar"|code-block|syntax|javascript|1685702|如果需要一种方法，请使用store|offset|length|style|CODE|1685703|h.store(:key,+"bar")|1685704|如果您真的真的想要使用“铲子”运算符(<<)，那么它实际上是作为一个数组附加到散列值的后面，并且您必须指定键：|1685705|h[:key]+<<+"bar"|1685706|仅当密钥存在时，上述操作才有效。要追加一个新的键，您必须使用默认值初始化散列，您可以这样做：|1685707|h+=+Hash.new+{%7Ch,+k%7C+h[k]+=+''}
h[:key]+<<+"bar"|1685708|你可能会想用猴子补丁Hash来包含一个以你所写的方式工作的铲子操作符：|1685709|class+Hash
++def+<<(k,v)
++++self.store(k,v)
++end
end|1685710|然而，这并不继承在其他上下文中应用于铲子操作符的“语法糖”：|1685711|h+<<+:key,+"bar"+#doesn't+work
h.<<+:key,+"bar"+#works|1685712|entityMap^0|0|0|0|C|5|0|0|J|2|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|18|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|19|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|1B|8|@$K|1C|L|1D|M|N]]|9|@]|A|$]]|$1|O|3|P|5|F|7|1E|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|1F|8|@$K|1G|L|1H|M|N]]|9|@]|A|$]]|$1|S|3|T|5|F|7|1I|8|@]|9|@]|A|$G|H]]|$1|U|3|V|5|6|7|1J|8|@]|9|@]|A|$]]|$1|W|3|X|5|F|7|1K|8|@]|9|@]|A|$G|H]]|$1|Y|3|Z|5|6|7|1L|8|@]|9|@]|A|$]]|$1|10|3|11|5|F|7|1M|8|@]|9|@]|A|$G|H]]|$1|12|3|13|5|6|7|1N|8|@]|9|@]|A|$]]|$1|14|3|15|5|F|7|1O|8|@]|9|@]|A|$G|H]]|$1|16|3|-4|5|6|7|1P|8|@]|9|@]|A|$]]]|17|$]]

Since hashes aren't inherently ordered, there isn't a notion of appending. Ruby hashes since 1.9 maintain insertion order, however. Here are the ways to add new key/value pairs.

The simplest solution is 

<pre><code>h[:key] = "bar"
</code></pre>

If you want a method, use <code>store</code>:

<pre><code>h.store(:key, "bar")
</code></pre>

If you really, really want to use a "shovel" operator (<code>&lt;&lt;</code>), it is actually appending to the value of the hash as an array, and you must specify the key:

<pre><code>h[:key] &lt;&lt; "bar"
</code></pre>

The above only works when the key exists. To append a new key, you have to initialize the hash with a default value, which you can do like this:

<pre><code>h = Hash.new {|h, k| h[k] = ''}
h[:key] &lt;&lt; "bar"
</code></pre>

You may be tempted to monkey patch Hash to include a shovel operator that works in the way you've written:

<pre><code>class Hash
 def &lt;&lt;(k,v)
 self.store(k,v)
 end
end
</code></pre>

However, this doesn't inherit the "syntactic sugar" applied to the shovel operator in other contexts:

<pre><code>h &lt;&lt; :key, "bar" #doesn't work
h.&lt;&lt; :key, "bar" #works
</code></pre>

blocks|key|1899294|text|我不得不做类似的事情，但我需要用相同的键来加值。当我使用merge或update时，我不能推送具有相同键的值。所以我不得不使用哈希数组。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1899295|++++my_hash_static+=+{:header+=>{:company+=>+'xx',+:usercode+=>+'xx',+:password+=>+'xx',
++++++++++++++++++++++:type=>+'n:n',+:msgheader+=>+from},+:body=>[]}
++++my_hash_dynamic+=+{:mp=>{:msg=>message,+:no=>phones}+}++++++++
++++my_hash_full+=+my_hash_static[:body].push+my_hash_dynamic|code-block|syntax|javascript|1899296|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I had to do a similar thing but I needed to add values with same keys. When I use merge or update I can't push values with same keys. So I had to use array of hashes. 

<pre><code> my_hash_static = {:header =&gt;{:company =&gt; 'xx', :usercode =&gt; 'xx', :password =&gt; 'xx',
 :type=&gt; 'n:n', :msgheader =&gt; from}, :body=&gt;[]}
 my_hash_dynamic = {:mp=&gt;{:msg=&gt;message, :no=&gt;phones} } 
 my_hash_full = my_hash_static[:body].push my_hash_dynamic
</code></pre>

In Ruby, one can append values to existing arrays using &lt;&lt;:

<pre><code>a = []
a &lt;&lt; "foo"
</code></pre>

but, can you also append key/value pairs to an existing hash?

<pre><code>h = {}
h &lt;&lt; :key "bar"
</code></pre>

I know you can do:

<pre><code>h[:key] = ""
h[:key] &lt;&lt; "bar"
</code></pre>

but that's not I want.

Thanks.

Append key/value pair to hash with << in Ruby

在Ruby中，可以使用<<将值追加到现有数组中：a = []a << "foo"但是，您还可以将键/值对附加到现有散列中吗？h = {}h << :key "bar"我知道你能做到：h[:key] = ""h[:key] << "bar"但那不是我想要的。谢谢。

问在Ruby语言中使用<<将键/值对附加到散列
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