Hi, I have list like this
[%{"date" => "30-04-2021", "minimumAmount" => "10000"}, %{"date" => "30-07-2021", "minimumAmount" => "10000"}, %{"date" => "30-011-2021", "minimumAmount" => "5000"}]
From this i have to iterate each map and minimumAmount value should get added to previous minimumAmount value. How can i achieve this like below?
[%{“date” => “30-04-2021”, “minimumAmount” => “10000”}, %{“date” => “30-07-2021”, “minimumAmount” => “20000”}, %{“date” => “30-011-2021”, “minimumAmount” => “25000”}]
Thank You
You need to iterate the list and pass the previous sum.
Enum.reduce, or simple recursion should do it.
For example using an acc like {[], 0}
You also need to parse string to integer in the process…
My question is the same. How can i store the previous sum value as another variable, to add it to newly coming value.
The 0 is the previous sum value in the acc.
It would look like this…
{list, _} = Enum.reduce(list, {[], 0}, fn %{"minimumAmount" => ma_str} = x, {l, sum} ->
new_sum = sum + String.to_integer(ma_str)
{[%{x | "minimumAmount" => to_string(new_sum)} | l], new_sum}
end)
At the end, You might want to reverse the list.
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As @kokolegorille have said, you can reduce the list using an accumulator
Enum.reduce(your_list, 0, fn x, acc → acc + String.to_integer(x[“minimumAmount”]) end)
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You probably need to pass a list as well in the acc, because it is the return value.
you are right:), so @Nishanthg follow the @kokolegorille answer.
My solution only returns the sum of minimum amounts.