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| title |
|---|
| Enumerables |
Enumerables (Enum)
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.
Example
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.
iex> Enum.map([1, 2, 3], fn(x) -> x * 2 end)
[2, 4, 6]
Methods in the Enum Module
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.
Enum.map
Enum.map runs an anonymous or captured function over a list.
iex> Enum.map([5, 10, 15, 20], fn(x) -> x * 2 end)
[10, 20, 30, 40]