28 lines
1.3 KiB
Markdown
28 lines
1.3 KiB
Markdown
---
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title: Enumerables
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---
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## Enumerables (Enum)
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In object oriented programming languages, you'll use a "loop" to perform the same action over and over on a piece of data, in Elixir since variables are immutable its not possible to create a tradational loop, instead Elixir and other functional programming languages rely on recursion. With recursion you'll run the same action over each item in a list without the need to mutate a variable. The Enum library built in Elixir makes this easy.
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## Example
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Using `Enum.map` you can run an anonymous function (function that's not inside a module) passing over each item in a list. This accomplishes the same task as a tradational loop without needing to mutate an accumulator variable.
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```elixir
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iex> Enum.map([1, 2, 3], fn(x) -> x * 2 end)
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[2, 4, 6]
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```
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## Methods in the Enum Module
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The Enum module has over 70 different functions to use on Enumerables, listing them all here would take up a few pages. Instead let's look at the most commonly used functions in the Enum Module.
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### Enum.map
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`Enum.map` runs an anonymous or captured function over a list.
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```elixir
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iex> Enum.map([5, 10, 15, 20], fn(x) -> x * 2 end)
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[10, 20, 30, 40]
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```
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#### More Information:
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* [elixir-lang.org | recursion](https://elixir-lang.org/getting-started/enumerables-and-streams.html)
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* [hexdocs | Enum](https://hexdocs.pm/elixir/Enum.html)
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