使用整数键创建地图 [英] Create a Map with an Integer Key

问题描述

我想用整数类型的键创建一个映射，但这不起作用:

I want to create a map with a key of type integer, but this doesn't work:

iex(1)> a = %{3: "fdsfd"}
** (SyntaxError) iex:1: unexpected token: ":" (column 8, codepoint U+003A)

iex(1)> a = %{:3 => "fdsfd"}
** (SyntaxError) iex:1: unexpected token: ":" (column 7, codepoint U+003A)

推荐答案

要将Integer用作键，只需像这样使用它即可:

To use an Integer as a key, simply use it like this:

map = %{ 3 => "value" }

---

:3在Elixir中是无效值；在Elixir中，原子既不是字符串也不是整数，它们是常量，其名称就是它们的值.要使用仅以3作为原子的键，则必须使用以下命令:

---

:3 is an invalid value in Elixir; atoms are neither Strings or Integers in Elixir, they are constants where their name is their value. To use a key with only 3 as an atom, you would have to use this:

map = %{ :"3" => "value" }

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