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List.Contains

Indicates whether the list contains the value.

Syntax​

List.Contains(
    list as list,
    value as any,
    optional equationCriteria as any
) as logical

Remarks​

Indicates whether the list contains the specified value. Returns true if the value is found in the list, false otherwise.

  • list: The list to search.
  • value: The value to search for in the list.
  • equationCriteria: (Optional) The comparer used to determine if two values are equal.

Examples​

Example #1​

Determine if the list {1, 2, 3, 4, 5} contains 3.

List.Contains({1, 2, 3, 4, 5}, 3)

Result:

true

Example #2​

Determine if the list {1, 2, 3, 4, 5} contains 6.

List.Contains({1, 2, 3, 4, 5}, 6)

Result:

false

Example #3​

Ignoring case, determine if the list contains "rhubarb".

List.Contains({"Pears", "Bananas", "Rhubarb", "Peaches"},
    "rhubarb",
    Comparer.OrdinalIgnoreCase
)

Result:

true

Example #4​

Determine if the list contains the date April 8, 2022.

let
    Source = {#date(2024, 2, 23), #date(2023, 12, 2), #date(2022, 4, 8), #date(2021, 7, 6)},
    ContainsDate = List.Contains(Source, Date.From("4/8/2022"))
in
    ContainsDate

Result:

true

Category​

List.Membership functions

More examples​

Implement this function to retrieve or calculate the service URL based on the data source path parameters

GetAuthorizationUrlFromWwwAuthenticate = (url as text) as text =>
    let
        // Sending an unauthenticated request to the service returns
        // a 302 status with WWW-Authenticate header in the response. The value will
        // contain the correct authorization_uri.
        // 
        // Example:
        // Bearer authorization_uri="https://login.microsoftonline.com/{tenant_guid}/oauth2/authorize"
        responseCodes = {302, 401},
        endpointResponse = Web.Contents(url, [
            ManualCredentials = true,
            ManualStatusHandling = responseCodes
        ])
    in
        if (List.Contains(responseCodes, Value.Metadata(endpointResponse)[Response.Status]?)) then
            let
                headers = Record.FieldOrDefault(Value.Metadata(endpointResponse), "Headers", []),
                wwwAuthenticate = Record.FieldOrDefault(headers, "WWW-Authenticate", ""),
                split = Text.Split(Text.Trim(wwwAuthenticate), " "),
                authorizationUri = List.First(List.Select(split, each Text.Contains(_, "authorization_uri=")), null)
            in
                if (authorizationUri <> null) then
                    // Trim and replace the double quotes inserted before the url
                    Text.Replace(Text.Trim(Text.Trim(Text.AfterDelimiter(authorizationUri, "=")), ","), """", "")
                else
                    error Error.Record("DataSource.Error", "Unexpected WWW-Authenticate header format or value during authentication.", [
                        #"WWW-Authenticate" = wwwAuthenticate
                    ])
        else
            error Error.Unexpected("Unexpected response from server during authentication.");