A typed array of 8-bit unsigned integer values. The contents are initialized to 0. If the requested number of bytes could not be allocated an exception is raised.
Syntax
uint8Array = new Uint8Array( length );
uint8Array = new Uint8Array( array );
uint8Array = new Uint8Array( buffer, byteOffset, length);
Parameters
uint8Array
Required. The variable name to which the Uint8Array object is assigned.
length
Specifies the number of elements in the array.
array
The array (or typed array) that is contained in this array. The contents are initialized to the contents of the given array or typed array, with each element converted to the Uint8 type.
buffer
The ArrayBuffer that the Uint8Array represents.
byteOffset
Optional. Specifies the offset in bytes from the start of the buffer at which the Uint8Array should begin.
length
The number of elements in the array.
Constants
The following table lists the constants of the Uint8Arrayobject.
| Constant | Description |
|---|---|
| BYTES_PER_ELEMENT Constant | The size in bytes of each element in the array. |
Properties
The following table lists the constants of the Uint8Arrayobject.
| Property | Description |
|---|---|
| buffer Property | Read-only. Gets the ArrayBuffer that is referenced by this array. |
| byteLength Property | Read-only. The length of this array from the start of its ArrayBuffer, in bytes, as fixed at construction time. |
| byteOffset Property | Read-only. The offset of this array from the start of its ArrayBuffer, in bytes, as fixed at construction time. |
| length Property | The length of the array. |
Methods
The following table lists the methods of the Uint8Arrayobject.
| Method | Description |
|---|---|
| set Method (Uint8Array) | Sets a value or an array of values. |
| subarray Method (Uint8Array) | Gets a new Uint8Array view of the ArrayBuffer store for this array. |
Example
The following example shows how to use a Uint8Array 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 Uint8Array(buffer.byteLength);
for (var i = 0; i < ints.length; i++) {
ints[i] = dataview.getUint8(i);
}
alert(ints[10]);
}
}
Requirements
Supported in the following document modes: Internet Explorer 10 standards and Internet Explorer 11 standards. Also supported in Store apps (Windows 8 and Windows Phone 8.1). See Version Information.
Not supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards.