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Row

This documentation reflects Arrow JS v4.0. Needs to be updated for the new Arrow API in v9.0 +.

A Row is an Object that retrieves each value at a certain index across a collection of child Vectors. Rows are returned from the get() function of the nested StructVector and MapVector, as well as RecordBatch and Table.

A Row defines read-only accessors for the indices and (if applicable) names of the child Vectors. For example, given a StructVector with the following schema:

const children = [
    Int32Vector.from([0, 1]),
    Utf8Vector.from(['foo', 'bar'])
];

const type = new Struct<{ id: Int32, value: Utf8 }>([
    new Field('id', children[0].type),
    new Field('value', children[1].type)
]);

const vector = new StructVector(Data.Struct(type, 0, 2, 0, null, children));

const row = vector.get(1);

assert((row[0] ===   1  ) && (row.id    === row[0]));
assert((row[1] === 'bar') && (row.value === row[1]));

Row implements the Iterator interface, enumerating each value in order of the child vectors list.

Notes:

  • If the Row's parent type is a Struct, Object.getOwnPropertyNames(row) returns the child vector indices.
  • If the Row's parent type is a Map, Object.getOwnPropertyNames(row) returns the child vector field names, as defined by the children Fields list of the Map instance.

Methods​

[key: string]: T[keyof T]['TValue']​

[kParent]: MapVector<T> | StructVector<T>​

[kRowIndex]: number​

[kLength]: number (readonly)​

[Symbol.iterator](): IterableIterator<T[keyof T]["TValue"]>​

get(key: K): T[K]["TValue"]​

Returns the value at the supplied key, where key is either the integer index of the set of child vectors, or the name of a child Vector

toJSON(): any​

toString(): any​