Int32Array() constructor
The Int32Array()
typed array constructor creates an array
of twos-complement 32-bit signed integers in the platform byte order. If control over
byte order is needed, use DataView
instead. 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).
Syntax
new Int32Array(); // new in ES2017
new Int32Array(length);
new Int32Array(typedArray);
new Int32Array(object);
new Int32Array(buffer);
new Int32Array(buffer, byteOffset);
new Int32Array(buffer, byteOffset, length);
Description
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 Int32Array
// From a length
const int32 = new Int32Array(2);
int32[0] = 42;
console.log(int32[0]); // 42
console.log(int32.length); // 2
console.log(int32.BYTES_PER_ELEMENT); // 4
// From an array
const x = new Int32Array([21, 31]);
console.log(x[1]); // 31
// From another TypedArray
const y = new Int32Array(x);
console.log(y[0]); // 21
// From an ArrayBuffer
const buffer = new ArrayBuffer(32);
const z = new Int32Array(buffer, 4, 4);
console.log(z.byteOffset); // 4
// From an iterable
const iterable = function*() { yield* [1, 2, 3]; }();
const int32FromIterable = new Int32Array(iterable);
console.log(int32FromIterable);
// Int32Array [1, 2, 3]
Specifications
Specification |
---|
ECMAScript Language Specification # sec-typedarray-constructors |
Browser compatibility
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