DataView
Baseline Widely available *
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
* Some parts of this feature may have varying levels of support.
The DataView
view provides a low-level interface for reading and writing multiple number types in a binary ArrayBuffer
, without having to care about the platform's endianness.
Description
Endianness
Multi-byte number formats are represented in memory differently depending on machine architecture — see Endianness for an explanation. DataView
accessors provide explicit control of how data is accessed, regardless of the executing computer's endianness. For example, WebAssembly memory is always little-endian, so you should use DataView
instead of typed arrays to read and write multi-byte values. See WebAssembly.Memory
for an example.
const littleEndian = (() => { const buffer = new ArrayBuffer(2); new DataView(buffer).setInt16(0, 256, true /* littleEndian */); // Int16Array uses the platform's endianness. return new Int16Array(buffer)[0] === 256; })(); console.log(littleEndian); // true or false
Note:DataView
defaults to big-endian read and write, but most platforms use little-endian.
Constructor
DataView()
Creates a new
DataView
object.
Instance properties
These properties are defined on DataView.prototype
and shared by all DataView
instances.
DataView.prototype.buffer
The
ArrayBuffer
referenced by this view. Fixed at construction time and thus read only.DataView.prototype.byteLength
The length (in bytes) of this view. Fixed at construction time and thus read only.
DataView.prototype.byteOffset
The offset (in bytes) of this view from the start of its
ArrayBuffer
. Fixed at construction time and thus read only.DataView.prototype.constructor
The constructor function that created the instance object. For
DataView
instances, the initial value is theDataView
constructor.DataView.prototype[Symbol.toStringTag]
The initial value of the
[Symbol.toStringTag]
property is the string"DataView"
. This property is used inObject.prototype.toString()
.
Instance methods
DataView.prototype.getBigInt64()
Reads 8 bytes starting at the specified byte offset of this
DataView
and interprets them as a 64-bit signed integer.DataView.prototype.getBigUint64()
Reads 8 bytes starting at the specified byte offset of this
DataView
and interprets them as a 64-bit unsigned integer.DataView.prototype.getFloat16()
Reads 2 bytes starting at the specified byte offset of this
DataView
and interprets them as a 16-bit floating point number.DataView.prototype.getFloat32()
Reads 4 bytes starting at the specified byte offset of this
DataView
and interprets them as a 32-bit floating point number.DataView.prototype.getFloat64()
Reads 8 bytes starting at the specified byte offset of this
DataView
and interprets them as a 64-bit floating point number.DataView.prototype.getInt16()
Reads 2 bytes starting at the specified byte offset of this
DataView
and interprets them as a 16-bit signed integer.DataView.prototype.getInt32()
Reads 4 bytes starting at the specified byte offset of this
DataView
and interprets them as a 32-bit signed integer.DataView.prototype.getInt8()
Reads 1 byte at the specified byte offset of this
DataView
and interprets it as an 8-bit signed integer.DataView.prototype.getUint16()
Reads 2 bytes starting at the specified byte offset of this
DataView
and interprets them as a 16-bit unsigned integer.DataView.prototype.getUint32()
Reads 4 bytes starting at the specified byte offset of this
DataView
and interprets them as a 32-bit unsigned integer.DataView.prototype.getUint8()
Reads 1 byte at the specified byte offset of this
DataView
and interprets it as an 8-bit unsigned integer.DataView.prototype.setBigInt64()
Takes a BigInt and stores it as a 64-bit signed integer in the 8 bytes starting at the specified byte offset of this
DataView
.DataView.prototype.setBigUint64()
Takes a BigInt and stores it as a 64-bit unsigned integer in the 8 bytes starting at the specified byte offset of this
DataView
.DataView.prototype.setFloat16()
Takes a number and stores it as a 16-bit float in the 2 bytes starting at the specified byte offset of this
DataView
.DataView.prototype.setFloat32()
Takes a number and stores it as a 32-bit float in the 4 bytes starting at the specified byte offset of this
DataView
.DataView.prototype.setFloat64()
Takes a number and stores it as a 64-bit float in the 8 bytes starting at the specified byte offset of this
DataView
.DataView.prototype.setInt16()
Takes a number and stores it as a 16-bit signed integer in the 2 bytes at the specified byte offset of this
DataView
.DataView.prototype.setInt32()
Takes a number and stores it as a 32-bit signed integer in the 4 bytes at the specified byte offset of this
DataView
.DataView.prototype.setInt8()
Takes a number and stores it as an 8-bit signed integer in the byte at the specified byte offset of this
DataView
.DataView.prototype.setUint16()
Takes a number and stores it as a 16-bit unsigned integer in the 2 bytes at the specified byte offset of this
DataView
.DataView.prototype.setUint32()
Takes a number and stores it as a 32-bit unsigned integer in the 4 bytes at the specified byte offset of this
DataView
.DataView.prototype.setUint8()
Takes a number and stores it as an 8-bit unsigned integer in the byte at the specified byte offset of this
DataView
.
Examples
Using DataView
const buffer = new ArrayBuffer(16); const view = new DataView(buffer, 0); view.setInt16(1, 42); view.getInt16(1); // 42
Specifications
Specification |
---|
ECMAScript® 2026 Language Specification # sec-dataview-objects |