firstWhere()

Get the first matching accessible document in the collection.

Signature

firstWhere(predicate: () => Boolean)): <Collection> | Null

firstWhere(predicate: (val: Document) => Boolean)): <Collection> | Null

Description

Returns the first accessible document in the collection that matches the predicate function. Otherwise, returns null.

The predicate function must return a Boolean.

Parameters

Parameter Type Required Description

predicate

Function

Anonymous function that compares values in each document in the collection and returns true for matches or false for mismatches.

predicate parameters:

Parameter Type Required Description

val

Document

Collection document to compare. If omitted, use dot notation to access document properties.

Return value

One of:

Type Description

Document

First accessible document matching the predicate function.

Null

When no document matches the predicate function or all matching documents are inaccessible.

Examples

Letter.firstWhere(.letter < 'Z')
{
  id: "357101835888099361",
  coll: Letter,
  ts: Time("2023-02-19T14:41:39.230Z"),
  name: "A"
}

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