Atomics.exchange()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since December 2021.
The Atomics.exchange()
static method exchanges a given value at a given position in the array and returns the old value at that position. This atomic operation guarantees that no other write happens between the read of the old value and the write of the new value.
Try it
Syntax
Atomics.exchange(typedArray, index, value)
Parameters
typedArray
-
An integer typed array. One of
Int8Array
,Uint8Array
,Int16Array
,Uint16Array
,Int32Array
,Uint32Array
,BigInt64Array
, orBigUint64Array
. index
-
The position in the
typedArray
to exchange avalue
. value
-
The number to exchange.
Return value
The old value at the given position (typedArray[index]
).
Exceptions
TypeError
-
Thrown if
typedArray
is not one of the allowed integer types. RangeError
-
Thrown if
index
is out of bounds in thetypedArray
.
Examples
Using exchange()
const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);
Atomics.exchange(ta, 0, 12); // returns 0, the old value
Atomics.load(ta, 0); // 12
Specifications
Specification |
---|
ECMAScript Language Specification # sec-atomics.exchange |
Browser compatibility
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