Elixirの対話モードでコレクションの動作を確認してみた

概要

Elixirの対話モードでコクションの動作を確認してみました。以下のページを参考にしました。

対話モードで実行

以下のコマンドを実行しました。

$ iex
Erlang/OTP 24 [erts-12.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit]

Interactive Elixir (1.12.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> [3.14, :pie, "Apple"]
[3.14, :pie, "Apple"]
iex(2)> list = [3.14, :pie, "Apple"]
[3.14, :pie, "Apple"]
iex(3)> ["π" | list]
["π", 3.14, :pie, "Apple"]
iex(4)> list ++ ["Cherry"]
[3.14, :pie, "Apple", "Cherry"]
iex(5)> [1, 2] ++ [3, 4, 1]
[1, 2, 3, 4, 1]
iex(6)> ["foo", :bar, 42] -- [42, "bar"]
["foo", :bar]
iex(7)> [1,2,2,3,2,3] -- [1,2,3,2]
[2, 3]
iex(8)> [2] -- [2.0]
[2]
iex(9)> [2.0] -- [2.0]
[]
iex(10)> hd [3.14, :pie, "Apple"]
3.14
iex(11)> tl [3.14, :pie, "Apple"]
[:pie, "Apple"]
iex(12)> [head | tail] = [3.14, :pie, "Apple"]
[3.14, :pie, "Apple"]
iex(13)> head
3.14
iex(14)> tail
[:pie, "Apple"]
iex(15)> {3.14, :pie, "Apple"}
{3.14, :pie, "Apple"}
iex(16)> File.read("./file")
{:ok, ""}
iex(17)> File.read("./file2")
{:error, :enoent}
iex(18)> [foo: "bar", hello: "world"]
[foo: "bar", hello: "world"]
iex(19)> [{:foo, "bar"}, {:hello, "world"}]
[foo: "bar", hello: "world"]
iex(20)> map = %{:foo => "bar", "hello" => :world}
%{:foo => "bar", "hello" => :world}
iex(21)> map[:foo]
"bar"
iex(22)> map["hello"]
:world
iex(23)> key = "hello"
"hello"
iex(24)> %{key => "world"}
%{"hello" => "world"}
iex(25)> %{:foo => "bar", :foo => "hello world"}
warning: key :foo will be overridden in map
  iex:25

%{foo: "hello world"}
iex(26)> %{foo: "bar", hello: "world"}
%{foo: "bar", hello: "world"}
iex(27)> %{foo: "bar", hello: "world"} == %{:foo => "bar", :hello => "world"}
true
iex(28)> map = %{foo: "bar", hello: "world"}
%{foo: "bar", hello: "world"}
iex(29)> map.hello
"world"
iex(30)> map = %{foo: "bar", hello: "world"}
%{foo: "bar", hello: "world"}
iex(31)> %{map | foo: "baz"}
%{foo: "baz", hello: "world"}
iex(32)> map = %{hello: "world"}
%{hello: "world"}
iex(33)> %{map | foo: "baz"}
** (KeyError) key :foo not found in: %{hello: "world"}
    (stdlib 3.17) :maps.update(:foo, "baz", %{hello: "world"})
    (stdlib 3.17) erl_eval.erl:256: anonymous fn/2 in :erl_eval.expr/5
    (stdlib 3.17) lists.erl:1267: :lists.foldl/3
iex(33)> Map.put(map, :foo, "baz")
%{foo: "baz", hello: "world"}
iex(34)> 

まとめ

何かの役に立てばと。