List.PositionOf

Επιστρέφει τις αποκλίσεις μιας τιμής σε μια λίστα.

Syntax

List.PositionOf(
    list as list,
    value as any,
    optional occurrence as Occurrence.Type,
    optional equationCriteria as any
) as any

Remarks

Returns the offset at which the specified value appears in a list. Returns -1 if the value doesn't appear.

• list: The list to search.
• value: The value to find in the list.
• occurrence: (Optional) The specific occurrence to report. This value can be Occurrence.First, Occurrence.Last, or Occurrence.All. If no occurrence is specified, Occurrence.First is used.
• 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.

Examples

Example #1

Βρείτε τη θέση στη λίστα {1, 2, 3} όπου εμφανίζεται η τιμή 3.

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

Result:

2

Example #2

Βρείτε τη θέση στη λίστα με όλες τις παρουσίες ημερομηνιών από το 2022.

let
    Source = {
        #date(2021, 5, 10),
        #date(2022, 6, 28),
        #date(2023, 7, 15),
        #date(2022, 12, 31),
        #date(2022, 4, 8),
        #date(2024, 3, 20)
    },
    YearList = List.Transform(Source, each Date.Year(_)),
    TargetYear = 2022,
    FindPositions = List.PositionOf(YearList, TargetYear, Occurrence.All)
in
    FindPositions

Result:

{1, 3, 4}

Example #3

Find the position in the list of the last occurrence of the word dog, ignoring case.

let
    Source = List.PositionOf(
        {"dog", "cat", "DOG", "pony", "bat", "rabbit", "dOG"},
        "dog",
        Occurrence.Last,
        Comparer.OrdinalIgnoreCase
    )
in
    Source

Result:

6

Example #4

Βρείτε τη θέση στη λίστα που βρίσκεται μέσα σε δύο μονάδες του αριθμού 28.

let
    Source = { 10, 15, 20, 25, 30 },
    Position = List.PositionOf(
        Source,
        28,
        Occurrence.First,
        (x, y) => Number.Abs(x - y) <= 2
    )
in
    Position

Result:

4

Category

List.Membership functions