DataView

Summary

You can use a DataView object to read and write the different kinds of binary data to any location in the ArrayBuffer.

Syntax

dataView = new DataView( DataView( buffer , byteOffset , byteLength ));

dataView

Required. The variable name to which the DataView object is assigned.

buffer

The ArrayBuffer that the DataView represents.

byteOffset

Optional. Specifies the offset in bytes from the start of the buffer at which the DataView should begin.

byteLength

Optional. Specifies the length (in bytes) of the section of the buffer that the DataView should represent.

Examples

The following example shows how to use a DataView object to process the binary data acquired from an XmlHttpRequest:

var req = new XMLHttpRequest();
     req.open('GET', "http://www.example.com");
     req.responseType = "arraybuffer";
     req.send();

     req.onreadystatechange = function () {
         if (req.readyState === 4) {
             var buffer = req.response;
             var dataView = new DataView(buffer);
             var ints = new Int32Array(dataView.byteLength / 4);
             for (var i = 0; i < ints.length; i++) {
                 ints[i] = dataview.getInt32(i * 4);
             }
         alert(ints[10]);
         }
     }

Remarks

If both byteOffset and byteLength are omitted, the DataView spans the entire ArrayBuffer range. If the byteLength is omitted, the DataView extends from the given byteOffset until the end of the ArrayBuffer. If the given byteOffset and byteLength references an area beyond the end of the ArrayBuffer, an exception is raised.

Properties

The following table lists the properties of the DataView object.

Methods

The following table lists the methods of the DataView object.

Attributions

• Microsoft Developer Network: Article