Elixir:如何反转贴图(交换键和值)?
我有一张这样的地图:Elixir:如何反转贴图(交换键和值)?,elixir,Elixir,我有一张这样的地图: %{ "US" => "United States", "CA" => "Canada", "NL" => "The Netherlands" } %{ "United States" => "US", "Canada" => "CA", "The Netherlands" => "NL" } 我希望将键与值交换,从而生成如下映射: %{ "US" => "United States", "CA"
%{
"US" => "United States",
"CA" => "Canada",
"NL" => "The Netherlands"
}
%{
"United States" => "US",
"Canada" => "CA",
"The Netherlands" => "NL"
}
我希望将键与值交换,从而生成如下映射:
%{
"US" => "United States",
"CA" => "Canada",
"NL" => "The Netherlands"
}
%{
"United States" => "US",
"Canada" => "CA",
"The Netherlands" => "NL"
}
像这样“反转”或“反转”地图的最佳方法是什么?我在任何地方都看不到它的专用功能。一个简单的方法是使用
Map.new
。它使用一个函数,您可以在该函数中为每对指定新的键和值:
Map.new(map, fn {key, val} -> {val, key} end)
更多方法:
for {k, v} <- map, into: %{}, do: {v, k}
{k,v}的