将Array转换为Hash,同时在Ruby中保留Array索引值

Question

我有一个数组,其中包含X多个值.以下数组只有4个,但我需要代码是动态的,而不是只依赖于四个数组对象.

array = ["Adult", "Family", "Single", "Child"]

我想转换array为这样的哈希:

hash = {0 => 'Adult', 1 => 'Family', 2 => 'Single', 3 => 'Child'}

散列应该具有与数组具有对象一样多的键/值对,并且值应该从0开始并且对于每个对象递增1.

Answer 1

使用Enumerable#each_with_index:

Hash[array.each_with_index.map { |value, index| [index, value] }]
# => {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}

正如@hirolau评论的那样,each_with_index.map也可以写成map.with_index.

Hash[array.map.with_index { |value, index| [index, value] }]
# => {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}

UPDATE

Alterantive使用Hash#invert:

Hash[array.map.with_index{|*x|x}].invert
# => {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}
Hash[[*array.map.with_index]].invert
# => {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}

Answer 2

另一个：

Hash[array.each_index.zip(array)]
#=> {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}

较新的 Ruby 版本将允许：

array.each_with_index.to_h.invert
#=> {0=>"Adult", 1=>"Family", 2=>"Single", 3=>"Child"}