DataView() constructor

The DataView() constructor is used to create DataView objects.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

Syntax

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

Parameters

buffer

An existing ArrayBuffer or SharedArrayBuffer to use as the storage backing the new DataView object.

byteOffset Optional

The offset, in bytes, to the first byte in the above buffer for the new view to reference. If unspecified, the buffer view starts with the first byte.

byteLength Optional

The number of elements in the byte array. If unspecified, the view's length will match the buffer's length.

Return value

A new DataView object representing the specified data buffer. (That probably wasn't a very helpful description.)

You can think of the returned object as an "interpreter" of the array buffer of bytes — it knows how to convert numbers to fit within the buffer correctly, both when reading and writing to it. This means handling integer and float conversion, endianness, and other details of representing numbers in binary form.

Exceptions

RangeError

Thrown if the byteOffset or byteLength parameter values result in the view extending past the end of the buffer.

For example, if the buffer is 16 bytes long, the byteOffset is 8, and the byteLength is 10, this error is thrown because the resulting view tries to extend 2 bytes past the total length of the buffer.

Examples

Using DataView

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

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

Specifications

Browser compatibility

See also

• DataView