DataView

The DataView view provides a low-level interface for reading data from and writing it to an ArrayBuffer.

Syntax

new DataView(buffer [, byteOffset [, byteLength]])

Parameters

buffer
An existing ArrayBuffer to use as the storage for the new DataView object.
byteOffset Optional
The offset, in bytes, to the first byte in the specified buffer for the new view to reference. If not specified, the view of the buffer will start with the first byte.
byteLength Optional
The number of elements in the byte array. If unspecified, length of the view will match the buffer's length.

Return value

A new DataView object representing the specified data buffer.

Errors thrown

RangeError
Thrown if the byteOffset and byteLength result in the specified view extending past the end of the buffer.

Description

Detect endianness

You'll probably need to detect the type of architecture your script is running, here is a little trick to check it. See Endianness for more information.

var littleEndian = (function() {
  var buffer = new ArrayBuffer(2);
  new DataView(buffer).setInt16(0, 256, true);
  return new Int16Array(buffer)[0] === 256;
})();
console.log(littleEndian); // true or false

Properties

DataView.length
The DataView constructor's length property whose value is 3.
DataView.prototype
Allows the addition of properties to all DataView objects.

DataView instances

All DataView instances inherit from DataView.prototype.

Properties

{{page('en-US/Web/JavaScript/Reference/Global_Objects/DataView/prototype','Properties')}}

Methods

{{page('en-US/Web/JavaScript/Reference/Global_Objects/DataView/prototype','Methods')}}

Example

var buffer = new ArrayBuffer(16);
var dv = new DataView(buffer, 0);

dv.setInt16(1, 42);
dv.getInt16(1); //42

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'DataView' in that specification.
Standard Initial definition in an ECMA standard
Typed Array Specification Obsolete Superseded by ECMAScript 6

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 9.0 15.0 (15.0) 10 12.1 5.1
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 4.0 (Yes) 15.0 (15) ? 12.0 4.2

Firefox-specific notes

Starting with Gecko / SpiderMonkey 40 (Firefox 40 / Thunderbird 40 / SeaMonkey 2.37), DataView requires to be constructed with a new operator. Calling DataView() as a function without new, will throw a TypeError from now on.

var dv = DataView(buffer, 0);
// TypeError: calling a builtin DataView constructor without new is forbidden
var dv = new DataView(buffer, 0);

See also

  • jDataView: JavaScript library that polyfills and extends the DataView API to all browsers and Node.js.