Documentación offline JavaScript main
/ ó ⌘K

DataView.prototype.byteOffset

main Documentación oficial Licencia CC-BY-SA-2.5Descargado el 2026-08-02

En esta página

The byteOffset accessor property of {{jsxref("DataView")}} instances returns the offset (in bytes) of this view from the start of its {{jsxref("ArrayBuffer")}} or {{jsxref("SharedArrayBuffer")}}.

{{InteractiveExample("JavaScript Demo: DataView.prototype.byteOffset")}}

```js interactive-example // Create an ArrayBuffer with a size in bytes const buffer = new ArrayBuffer(16);

const view = new DataView(buffer, 12, 4); // From byte 12 for the next 4 bytes

console.log(view.byteOffset); // Expected output: 12

## Description

The `byteOffset` property is an accessor property whose set accessor function is `undefined`, meaning that you can only read this property. The value is established when the `DataView` is constructed and cannot be changed. However, the `byteOffset` becomes 0 if the underlying buffer is resized such that the viewed range is no longer valid.

## Examples

### Using the byteOffset property

```js
const buffer = new ArrayBuffer(8);
const dataview = new DataView(buffer);
dataview.byteOffset; // 0 (no offset specified)

const dataview2 = new DataView(buffer, 3);
dataview2.byteOffset; // 3 (as specified when constructing the DataView)

const buffer2 = new ArrayBuffer(16, { maxByteLength: 32 });
const dataviewLengthTracking = new DataView(buffer2, 4);
dataviewLengthTracking.byteOffset; // 4
buffer2.resize(3);
dataviewLengthTracking.byteOffset; // 0 (viewed range is no longer valid)

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#