How to Sort List Of Map By Map Value In Elixir?

To sort a list of maps by a specific key in Elixir, you can use the Enum.sort_by function along with a custom comparison function. First, you need to specify the key by which you want to sort the maps. Then, you can use Enum.sort_by to sort the list of maps based on that key. Here's an example code snippet:

1
2
3
4
5

list_of_maps = [%{key: 3}, %{key: 1}, %{key: 2}]

sorted_list = Enum.sort_by(list_of_maps, &(&1.key))

IO.inspect(sorted_list)

In this example, the list_of_maps is sorted based on the 'key' value in each map, resulting in a sorted_list where the maps are ordered by the 'key' value.

How to group the sorted list of map by map value in elixir?

You can achieve this by using the Enum.group_by function in Elixir. Here's an example of how you can group a sorted list of maps by a specific map value:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

list_of_maps = [
  %{name: "Alice", age: 30},
  %{name: "Bob", age: 25},
  %{name: "Charlie", age: 30},
  %{name: "David", age: 25}
]

sorted_list = Enum.sort(list_of_maps, fn map -> Map.get(map, :age) end)

grouped_by_age = Enum.group_by(sorted_list, fn map -> Map.get(map, :age) end)

IO.inspect(grouped_by_age)

In this example, we first define a list of maps with the keys name and age. We then sort the list of maps by the age key using Enum.sort. Finally, we use Enum.group_by to group the sorted list of maps by the age key. The grouped_by_age variable will be a map where the keys are the distinct age values and the values are lists of maps with that age value.

How to reverse the sorting order of list of map by map value in elixir?

One way to reverse the sorting order of a list of maps by a specific map value in Elixir is to use the Enum.sort_by/3 function along with the Kernel.< comparison operator.

Here's an example of how you can reverse the sorting order of a list of maps by a specific map value:

1
2
3
4
5

list_of_maps = [%{name: "Alice", age: 30}, %{name: "Bob", age: 25}, %{name: "Charlie", age: 35}]

sorted_list = Enum.sort_by(list_of_maps, &(&1.age), &>=/2)

IO.inspect(sorted_list)

In this example, we have a list of maps with name and age keys. We use Enum.sort_by/3 to sort the list of maps by the age value in descending order by using the &>=/2 function, which is the greater than or equal to comparison operator..

After running this code, the sorted_list will contain the list of maps sorted by the age value in descending order.

You can adjust the comparison operator to achieve different sorting orders as needed.

How to handle sorting list of map by map value in elixir for non-numeric values?

You can use the Enum.sort_by/2 function in Elixir to sort a list of maps by a specific map value. Here's an example of how you can sort a list of maps by a non-numeric map value:

1
2
3
4
5
6
7
8
9

list = [
  %{name: "Alice", age: 30},
  %{name: "Bob", age: 25},
  %{name: "Charlie", age: 35}
]

sorted_list = Enum.sort_by(list, &(&1[:name]))

IO.inspect(sorted_list)

In this example, the list variable contains a list of maps with name and age keys. We use the Enum.sort_by/2 function to sort the list of maps by the name value.

The &(&1[:name]) syntax is an anonymous function that returns the name value from each map in the list. The Enum.sort_by/2 function will sort the list of maps based on the values returned by this function.

After running this code, the sorted_list variable will contain the list of maps sorted alphabetically by the name value.

How to sort list of map by map value in elixir using custom sorting function?

You can sort a list of maps by a specific map value using a custom sorting function in Elixir. Here's an example of how you can do that:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

list_of_maps = [
  %{name: "Alice", age: 30},
  %{name: "Bob", age: 25},
  %{name: "Charlie", age: 35}
]

# Define a custom sorting function
def custom_sort(map1, map2) do
  map1_age = Map.get(map1, :age, 0)
  map2_age = Map.get(map2, :age, 0)
  
  if map1_age < map2_age do
    :lt
  elsif map1_age > map2_age do
    :gt
  else
    :eq
  end
end

# Sort the list of maps using the custom sorting function
sorted_list_of_maps = Enum.sort(list_of_maps, &custom_sort/2)

IO.inspect(sorted_list_of_maps)

In this example, we have a list of maps with name and age keys. We define a custom sorting function custom_sort that compares the age values of two maps. The function returns :lt if the first map's age value is less than the second map's age value, :gt if it's greater, and :eq if they are equal.

We then use Enum.sort to sort the list of maps based on the age values using the custom_sort function. The sorted list of maps is stored in sorted_list_of_maps and printed using IO.inspect.

You can customize the sorting logic in the custom_sort function based on your requirements.