List.Distinct

Syntax

List.Distinct(list as list, optional equationCriteria as any) as list

About

Returns a list that contains all the values in the specified list with duplicates removed. If the specified list is empty, the result is an empty list.

• list: The list from which distinct values are extracted.
• equationCriteria: (Optional) Specifies how equality is determined when comparing values. This parameter can be a key selector function, a comparer function, or a list containing both a key selector and a comparer.

Example 1

Remove the duplicates from the list {1, 1, 2, 3, 3, 3}.

Usage

List.Distinct({1, 1, 2, 3, 3, 3})

Output

{1, 2, 3}

Example 2

Starting at the end of the list, select the fruits that have a unique text length.

Usage

let
    Source = {"Apple", "Banana", "Cherry", "Date", "Fig"},
    Result = List.Distinct(List.Reverse(Source), each Text.Length(_))
in
    Result

Output

{"Fig", "Date", "Cherry", "Apple"}

Example 3

Starting at the beginning of the list, select the unique fruits while ignoring case.

Usage

let
    Source = {"apple", "Pear", "aPPle", "banana", "ORANGE", "pear", "Banana", "Cherry"},
    Result = List.Distinct(Source, Comparer.OrdinalIgnoreCase)
in
    Result

Output

{"apple", "Pear", "banana", "ORANGE", "Cherry"}

Example 4

Extract from a list of lists the first lists with unique country names while ignoring case. Place the extracted lists in the rows of a new table.

Usage

let
    Source = {
        {"USA", #date(2023, 8, 1), 567},
        {"canada", #date(2023, 8, 1), 254},
        {"Usa", #date(2023, 7, 1), 450},
        {"CANADA", #date(2023, 6, 1), 357},
        {"Panama", #date(2023, 6, 2), 20},
        {"panama", #date(2023, 7, 1), 40}
    },
    DistinctByCountry = List.Distinct(
        Source,
        {each _{0}, Comparer.OrdinalIgnoreCase}
    ),
    ToTable = Table.FromRows(DistinctByCountry, {"Country", "Date", "Value"}),
    ChangeTypes = Table.TransformColumnTypes(
        ToTable, {{"Country", type text}, {"Date", type date}, {"Value", Int64.Type}}
    )
in
    ChangeTypes

Output

#table(type table[Country = text, Date = date, Value = Int64.Type],
    {
        {"USA", #date(2023, 8, 1), 567},
        {"canada", #date(2023, 8, 1), 254},
        {"Panama", #date(2023, 6, 2), 20}
    }
)

Related content

Equation criteria