Hi there, I want to get the average height of a given list of people. Here is the associated code : people = [%{name: 'Mary', height: 160}, %{name: 'Paul', height: 180}, %{name: 'Hugo'}] heights = Enum.map(people, fn person -> Map.get(person, :height) end) …

I’d go for roughly the following as an avg function: def avg(list) list |> Enum.reduce({0, 0}, &avg/2) |> avg_finalize end defp avg(x, {sum, count}), do: {sum + x, count + 1} defp avg_finalize({sum, count}), do: sum / count The cool thing about this is, that you only need to iterate a singl…

Applying @NobbZ ’s approach to your specific situation, I’d be looking at something like: people = [%{name: 'Mary', height: 160}, %{name: 'Paul', height: 180}, %{name: 'Hugo'}] {total_height, count_people_with_height} = Enum.reduce(people, {0,0}, fn %{height: hei…

You are almost at the stage where it is easier to write the loop directly and not use Enum. :wink:

You say “loop” and that makes me wonder. I don’t see a good way to do it in one pass with a list comprehension. I can do it with recursion, but I prefer Enum.reduce defmodule Test do def avg(maps), do: avg(maps, {0,0}) def avg([], {total, count}) when count > 0, do: total / count def avg([%{h…

Thanks for your replies! I really appreciate ! I’m a totally noob with functional programming and elixir. This is far different from traditional OOP…

Hi, I am at very nascent stage in elixir , was wondering how can we achieve below case scenario in elixir var doctors=[ { doctorNumber: "#9", playedBy: "Christopher Eccleston", yearsPlayed: 1 }, { doctorNumber: "#10", playedBy: "David Tennant", yearsPlayed: 6 }, { doctorNumbe…

[image] matt212: var doctors=[ { doctorNumber: “#9”, playedBy: “Christopher Eccleston”, yearsPlayed: 1 }, { doctorNumber: “#10”, playedBy: “David Tennant”, yearsPlayed: 6 }, { doctorNumber: “#11”, playedBy: “Matt Smith”, yearsPlayed: 4 }, { doctorNumber: “#12”, pl…

Woah, thanks a lot ,excellent ! can we also club filter with existing map, just curious though ! doctors = doctors.filter(function(doctor) { return doctor.begin > 2000; // if truthy then keep item }).map(function(doctor) { return { // return what new object will look like doctorNumb…

[image] matt212: Woah, thanks a lot ,excellent ! can we also club filter with existing map, just curious though ! The ‘traditional’ Elixir way of writing that is in one of two forms, either via Enum piping: doctors |> Enum.filter(fn doctor -> doctor.begin > 2000 end) |> Enum.map(fn doctor -> …

Map, filter and reduce

Questions & Help Questions

NobbZ July 28, 2016, 11:27pm 6

My professor for functional programming used to say, that “loop” is just another word for recursion