The Int8Array()
constructor creates a typed array of twos-complement 8-bit signed integers. The contents are initialized to 0
. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
Int8Array() constructor
Syntax
new Int8Array(); // new in ES2017 new Int8Array(length); new Int8Array(typedArray); new Int8Array(object); new Int8Array(buffer); new Int8Array(buffer, byteOffset); new Int8Array(buffer, byteOffset, length);
Parameters
-
length
-
When called with a
length
argument, an internal array buffer is created in memory, of sizelength
multiplied byBYTES_PER_ELEMENT
bytes, containing zeros. -
typedArray
-
When called with a
typedArray
argument, which can be an object of any of the non-bigint typed-array types (such asInt32Array
), thetypedArray
gets copied into a new typed array. Each value intypedArray
is converted to the corresponding type of the constructor before being copied into the new array. The length of the new typed array will be same as the length of thetypedArray
argument. -
object
-
When called with an
object
argument, a new typed array is created as if by theTypedArray.from()
method. -
buffer
,byteOffset
,length
-
When called with a
buffer
, and optionally abyteOffset
and alength
argument, a new typed array view is created that views the specifiedArrayBuffer
. ThebyteOffset
andlength
parameters specify the memory range that will be exposed by the typed array view. If both are omitted, all ofbuffer
is viewed; if onlylength
is omitted, the remainder ofbuffer
is viewed.
Examples
Different ways to create an Int8Array
// From a length var int8 = new Int8Array(2); int8[0] = 42; console.log(int8[0]); // 42 console.log(int8.length); // 2 console.log(int8.BYTES_PER_ELEMENT); // 1 // From an array var arr = new Int8Array([21,31]); console.log(arr[1]); // 31 // From another TypedArray var x = new Int8Array([21, 31]); var y = new Int8Array(x); console.log(y[0]); // 21 // From an ArrayBuffer var buffer = new ArrayBuffer(8); var z = new Int8Array(buffer, 1, 4); // From an iterable var iterable = function*(){ yield* [1,2,3]; }(); var int8 = new Int8Array(iterable); // Int8Array[1, 2, 3]
Specifications
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
Int8Array |
7
|
12
|
4
|
10
|
11.6
|
5.1
|
4
|
18
|
4
|
12
|
4.2
|
1.0
|
1.0
|
0.10.0
|
constructor_without_parameters |
7
|
12
|
55
|
10
|
11.6
|
5.1
|
≤37
|
18
|
55
|
12
|
5
|
1.0
|
1.0
|
0.10.0
|
iterable_allowed |
39
|
14
|
52
|
No
|
26
|
10
|
39
|
39
|
52
|
26
|
10
|
4.0
|
1.0
|
4.0.0
|
new_required |
7
|
14
|
44
|
No
|
15
|
5.1
|
≤37
|
18
|
44
|
14
|
5
|
1.0
|
1.0
|
0.12.0
|
Compatibility notes
Starting with ECMAScript 2015, Int8Array
constructors require to be constructed with a new
operator. Calling a Int8Array
constructor as a function without new
, will throw a TypeError
from now on.
var dv = Int8Array([1, 2, 3]); // TypeError: calling a builtin Int8Array constructor // without new is forbidden
var dv = new Int8Array([1, 2, 3]);
See also
© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Int8Array/Int8Array