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 newDataView
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
andbyteLength
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Typed Array Specification | Obsolete | Superseded by ECMAScript 6 |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
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.