试试except!方法。

{:a => 1, :b => 2}.except!(:a)   #=> {:b => 2}

你可以用except!来自facets gem:

>> require 'facets' # or require 'facets/hash/except'
=> true
>> {:a => 1, :b => 2}.except(:a)
=> {:b=>2}

原来的哈希值不会改变。

编辑:正如Russel所说，facets有一些隐藏的问题，并且与ActiveSupport不完全兼容api。另一方面，ActiveSupport不像facet那样完整。最后，我将使用AS，并让边界情况出现在代码中。

如果delete返回哈希的delete对，那就太好了。 我这样做:

hash = {a: 1, b: 2, c: 3}
{b: hash.delete(:b)} # => {:b=>2}
hash  # => {:a=>1, :c=>3} 

在纯Ruby中:

{:a => 1, :b => 2}.tap{|x| x.delete(:a)}   # => {:b=>2}

有许多方法可以从散列中删除键并在Ruby中获取剩余的散列。

.slice => It will return selected keys and not delete them from the original hash. Use slice! if you want to remove the keys permanently else use simple slice. 2.2.2 :074 > hash = {"one"=>1, "two"=>2, "three"=>3} => {"one"=>1, "two"=>2, "three"=>3} 2.2.2 :075 > hash.slice("one","two") => {"one"=>1, "two"=>2} 2.2.2 :076 > hash => {"one"=>1, "two"=>2, "three"=>3} .delete => It will delete the selected keys from the original hash(it can accept only one key and not more than one). 2.2.2 :094 > hash = {"one"=>1, "two"=>2, "three"=>3} => {"one"=>1, "two"=>2, "three"=>3} 2.2.2 :095 > hash.delete("one") => 1 2.2.2 :096 > hash => {"two"=>2, "three"=>3} .except => It will return the remaining keys but not delete anything from the original hash. Use except! if you want to remove the keys permanently else use simple except. 2.2.2 :097 > hash = {"one"=>1, "two"=>2, "three"=>3} => {"one"=>1, "two"=>2, "three"=>3} 2.2.2 :098 > hash.except("one","two") => {"three"=>3} 2.2.2 :099 > hash => {"one"=>1, "two"=>2, "three"=>3} .delete_if => In case you need to remove a key based on a value. It will obviously remove the matching keys from the original hash. 2.2.2 :115 > hash = {"one"=>1, "two"=>2, "three"=>3, "one_again"=>1} => {"one"=>1, "two"=>2, "three"=>3, "one_again"=>1} 2.2.2 :116 > value = 1 => 1 2.2.2 :117 > hash.delete_if { |k,v| v == value } => {"two"=>2, "three"=>3} 2.2.2 :118 > hash => {"two"=>2, "three"=>3} .compact => It is used to remove all nil values from the hash. Use compact! if you want to remove the nil values permanently else use simple compact. 2.2.2 :119 > hash = {"one"=>1, "two"=>2, "three"=>3, "nothing"=>nil, "no_value"=>nil} => {"one"=>1, "two"=>2, "three"=>3, "nothing"=>nil, "no_value"=>nil} 2.2.2 :120 > hash.compact => {"one"=>1, "two"=>2, "three"=>3}

基于Ruby 2.2.2的结果。

onlineer普通红宝石，它只适用于红宝石> 1.9.x:

1.9.3p0 :002 > h = {:a => 1, :b => 2}
 => {:a=>1, :b=>2} 
1.9.3p0 :003 > h.tap { |hs| hs.delete(:a) }
 => {:b=>2} 

方法总是返回被调用的对象…

否则，如果你需要active_support/core_ext/hash(这在每个Rails应用程序中都是自动需要的)，你可以根据需要使用以下方法之一:

➜  ~  irb
1.9.3p125 :001 > require 'active_support/core_ext/hash' => true 
1.9.3p125 :002 > h = {:a => 1, :b => 2, :c => 3}
 => {:a=>1, :b=>2, :c=>3} 
1.9.3p125 :003 > h.except(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :004 > h.slice(:a)
 => {:a=>1} 

Except使用黑名单方法，因此它删除了所有作为参数列出的键，而slice使用白名单方法，因此它删除了所有没有作为参数列出的键。这些方法也存在bang版本(除了!和slice!)，它们修改给定的哈希，但它们的返回值不同，它们都返回哈希。它代表slice删除的键!还有为except保留的钥匙!：

1.9.3p125 :011 > {:a => 1, :b => 2, :c => 3}.except!(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :012 > {:a => 1, :b => 2, :c => 3}.slice!(:a)
 => {:b=>2, :c=>3}