我在
Ruby中有一个散列数组,如下所示：
domains = [
{ "country" => "Germany"},{"country" => "United Kingdom"},{"country" => "Hungary"},{"country" => "United States"},{"country" => "France"},{"country" => "Germany"},{"country" => "Slovakia"},{"country" => "Norway"},{"country" => "Norway"}
]
从这个散列数组我想创建一个新的哈希看起来像这样：
counted = {
"Germany" => "3","United Kingdom" => "United Kingdom","Hungary" => "3","United States" => "4","France" => "1"
}
有没有一个简单的方法来做这个使用Ruby 1.9？
解决方法
这个怎么样？
counted = Hash.new(0)
domains.each { |h| counted[h["country"]] += 1 }
counted = Hash[counted.map {|k,v| [k,v.to_s] }]