Vectors and Vector Types

info

This page is aligned to Apache Arrow JS v21.x (apache-arrow).

Vector construction is centered on the Vector class; Arrow no longer publishes long-lived public classes such as Int32Vector.

Usage

import {makeVector, Int32Array} from 'apache-arrow';

const ids = makeVector(new Int32Array([1, 2, 3]));
console.log(ids.length, ids.get(0));

import {vectorFromArray, Struct, Field, Int32, Utf8} from 'apache-arrow';

const rows = vectorFromArray(
  [{id: 1, label: 'alpha'}],
  new Struct([new Field('id', new Int32()), new Field('label', new Utf8())])
);

Factory functions

• makeVector<T extends TypedArray | BigIntArray>(data: T | readonly T[]): Vector
• makeVector<T extends DataView>(data: T | readonly T[]): Vector
• makeVector<T extends DataType>(data: Data<T> | readonly Data<T>[] | Vector<T> | readonly Vector<T>[] | DataProps<T> | readonly DataProps<T>[]): Vector<T>
• vectorFromArray(values: readonly unknown[], type?: DataType): Vector
• vectorFromArray<T extends readonly unknown[]>(values: T): Vector

Factory function behavior

• makeVector prefers typed-array input and zero-copy semantics when possible.
• vectorFromArray infers Arrow types from plain JS input and accepts optional explicit type overrides.

import {makeVector, vectorFromArray, Struct, Field, Int32, Utf8} from 'apache-arrow';

const a = makeVector(new Int32Array([1, 2, 3]));
const b = vectorFromArray(['a', 'b', 'c']);
const rows = vectorFromArray(
  [
    {id: 1, name: 'Alice'},
    {id: 2, name: 'Bob'}
  ],
  new Struct([new Field('id', new Int32()), new Field('name', new Utf8())])
);

Supported type families

Vector is shared across all Arrow logical type families:

• Null and boolean
• Integer and floating point
• Binary and text (Binary, Utf8, LargeBinary, LargeUtf8)
• Fixed-size list, list, struct, and map
• Temporal (Date*, Time*, Timestamp*)
• Interval, duration, dictionary, and union

For a full list of concrete DataType classes, see types.md.