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---
title: Atomics.xor()
slug: Web/JavaScript/Reference/Global_Objects/Atomics/xor
page-type: javascript-static-method
browser-compat: javascript.builtins.Atomics.xor
---
{{JSRef}}
The **`Atomics.xor()`** static
method computes a bitwise XOR 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.
{{EmbedInteractiveExample("pages/js/atomics-xor.html")}}
## Syntax
```js-nolint
Atomics.xor(typedArray, index, value)
```
### Parameters
- `typedArray`
- : An integer typed array. One of {{jsxref("Int8Array")}}, {{jsxref("Uint8Array")}},
{{jsxref("Int16Array")}}, {{jsxref("Uint16Array")}}, {{jsxref("Int32Array")}},
{{jsxref("Uint32Array")}}, {{jsxref("BigInt64Array")}}, or
{{jsxref("BigUint64Array")}}.
- `index`
- : The position in the `typedArray` to compute the bitwise XOR.
- `value`
- : The number to compute the bitwise XOR with.
### Return value
The old value at the given position (`typedArray[index]`).
### Exceptions
- {{jsxref("TypeError")}}
- : Thrown if `typedArray` is not one of the allowed integer types.
- {{jsxref("RangeError")}}
- : Thrown if `index` is out of bounds in the `typedArray`.
## Description
The bitwise XOR operation yields 1, if `a` and `b` are different.
The truth table for the XOR operation is:
| `a` | `b` | `a ^ b` |
| --- | --- | ------- |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
For example, a bitwise XOR of `5 ^ 1` results in `0100` which is
4 in decimal.
```plain
5 0101
1 0001
----
4 0100
```
## Examples
### Using xor
```js
const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);
ta[0] = 5;
Atomics.xor(ta, 0, 1); // returns 5, the old value
Atomics.load(ta, 0); // 4
```
## Specifications
{{Specifications}}
## Browser compatibility
{{Compat}}
## See also
- {{jsxref("Atomics")}}
- {{jsxref("Atomics.and()")}}
- {{jsxref("Atomics.or()")}}