Add / Remove key-value pairs from a Map

Question

How to add (and remove) key-value pairs in an Elixir map? This does not work:

map = %{a: 1, b: 2, c: 3}  map[:d] = 4 

Answer 1

Add to Map

Use Map.put(map, key, value):

map = Map.put(map, :d, 4) #=> %{a: 1, b: 2, c: 3, d: 4} 

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Remove from Map

Use Map.delete(map, key):

map = Map.delete(map, :b) #=> %{a: 1, c: 3}