Atomics.or()
The Atomics.or() static
method computes a bitwise OR with 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 until the modified value is written back.
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Syntax
Atomics.or(typedArray, index, value)
Parameters
typedArray-
An integer typed array. One of
Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,BigInt64Array, orBigUint64Array. index-
The position in the
typedArrayto compute the bitwise OR. value-
The number to compute the bitwise OR with.
Return value
The old value at the given position
(typedArray[index]).
Exceptions
TypeError-
Thrown if
typedArrayis not one of the allowed integer types. RangeError-
Thrown if
indexis out of bounds in thetypedArray.
Description
The bitwise OR operation yields 1, if either a or b are 1.
The truth table for the OR operation is:
a |
b |
a | b |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
For example, a bitwise OR of 5 | 1 results in 0101 which is 5
in decimal.
5 0101 1 0001 ---- 5 0101
Examples
Using or
const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);
ta[0] = 2;
Atomics.or(ta, 0, 1); // returns 2, the old value
Atomics.load(ta, 0); // 3
Specifications
| Specification |
|---|
| ECMAScript Language Specification # sec-atomics.or |
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