Enum find by id?

see: Enum.find_index/2

EDIT: OP did not post a map.

Note, that your map-items will be passed as {key, value} to the function.

See the example at the beginning of the Enum documentation:

map = %{"a" => 1, "b" => 2}
Enum.map(map, fn {k, v} -> {k, v * 2} end)
[{"a", 2}, {"b", 4}]

Didn’t get it… I understand that I can use find when I already have the element, like this /

Enum.find(alerts, fn x -> equal?(x, alert) end)
    |> case do
      nil -> alerts
      idx -> List.delete_at(alerts, idx)
    end

But when I want to find it by the property, I’m not being able to, tryed

 Enum.find(alerts, fn x -> equal?({:id}, alert_id) end)
    |> case do
      nil -> alerts
      idx -> List.delete_at(alerts, idx)
    end

and

Enum.find(alerts, fn {:id => id} -> equal?(id, alert_id) end)
    |> case do
      nil -> alerts
      idx -> List.delete_at(alerts, idx)
    end

But didn’t work

Sorry I overlooked that you want the index. I updated my answer.

But the question is how to find by property… The examples show how to find by equality, I currently don’t have the entire object, only the property(id) value

You want to (eg) find the index of the item with id==2 right?

[%{id: 1, foo: :bar}, %{id: 2, foo: :baz}, %{id: 3, foo: :foobar}]

So you want the index of {id: 2, foo: baz} which is 1…?

Edit: too much python today.

Exactly

find_index/2 will return the index of the first element, where the function you provide returns true.
So write that function.

Don`t like python, but C, C#, Javascript… I’m just new to Elixir, and didn’t spend enough time to learn it yet, but thank you for your help

Sorry I most likely confused you with the hint that map-items are given as {k, v} to the function.
You have a list of maps, So you just do:

e = [%{foo: :bar, id: 1}, %{foo: :baz, id: 2}, %{foo: :foobar, id: 3}]
iex(3)> Enum.find_index(e, fn v -> v.id == 1 end)                           
0

So find_index goes through the list element by element, calls the function you provide and if this function return true, the index is returned.

take a look at the great visual Elixir reference: