要散列的 Ruby 数组：每个元素都是键并从中派生出值
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Ruby array to hash: each element the key and derive value from it
提问by lulalala
I have an array of strings, and want to make a hash out of it. Each element of the array will be the key, and I want to make the value being computed from that key. Is there a Ruby way of doing this?
我有一个字符串数组，想从中得到一个散列。数组的每个元素都是键，我想根据该键计算出值。有没有 Ruby 的方式来做到这一点？
For example:
例如：
['a','b']to convert to {'a'=>'A','b'=>'B'}
['a','b']转换为 {'a'=>'A','b'=>'B'}
采纳答案by aidan
Ruby's each_with_objectmethod is a neat way of doing what you want
Ruby 的each_with_object方法是做你想做的事情的一种巧妙的方式
['a', 'b'].each_with_object({}) { |k, h| h[k] = k.upcase }
回答by Ricardo Acras
You can:
你可以：
a = ['a', 'b']
Hash[a.map {|v| [v,v.upcase]}]
回答by brad
%w{a b c}.reduce({}){|a,v| a[v] = v.upcase; a}
回答by Kassym Dorsel
Which ever way you look at it you will need to iterate the initial array. Here's another way :
无论您如何看待它，您都需要迭代初始数组。这是另一种方式：
a = ['a', 'b', 'c']
h = Hash[a.collect {|v| [v, v.upcase]}]
#=> {"a"=>"A", "b"=>"B", "c"=>"C"}
回答by Mark Thomas
Here's another way:
这是另一种方式：
a.zip(a.map(&:upcase)).to_h
#=>{"a"=>"A", "b"=>"B"}
回答by Jens Tinfors
Here's a naive and simple solution that converts the current character to a symbol to be used as the key. And just for fun it capitalizes the value. :)
这是一个天真而简单的解决方案，它将当前字符转换为要用作键的符号。只是为了好玩，它会将价值资本化。:)
h = Hash.new
['a', 'b'].each {|a| h[a.to_sym] = a.upcase}
puts h
# => {:a=>"A", :b=>"B"}
回答by Ismael Abreu
Not sure if this is the real Ruby way but should be close enough:
不确定这是否是真正的 Ruby 方式，但应该足够接近：
hash = {}
['a', 'b'].each do |x|
hash[x] = x.upcase
end
p hash # prints {"a"=>"A", "b"=>"B"}
As a function we would have this:
作为一个函数，我们会有这个：
def theFunk(array)
hash = {}
array.each do |x|
hash[x] = x.upcase
end
hash
end
p theFunk ['a', 'b', 'c'] # prints {"a"=>"A", "b"=>"B", "c"=>"C"}
回答by Joshua Pinter
.mapand .to_h
.map和 .to_h
[ 'a', 'b' ].map{ |element| [ element, element.upcase ] }.to_h
#=> {"a"=>"A", "b"=>"B"}
