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The SharedArrayBuffer.prototype.slice() method returns a new SharedArrayBuffer whose contents are a copy of this SharedArrayBuffer's bytes from begin, inclusive, up to end, exclusive. If either begin or end is negative, it refers to an index from the end of the array, as opposed to from the beginning. This method has the same algorithm as Array.prototype.slice().


sab.slice(begin, end)


begin Optional
Zero-based index at which to begin extraction.
A negative index can be used, indicating an offset from the end of the sequence. slice(-2) extracts the last two elements in the sequence.
If begin is undefined, slice begins from index 0.
end Optional
Zero-based index before which to end extraction. slice extracts up to but not including end.
For example, slice(1,4) extracts the second element through the fourth element (elements indexed 1, 2, and 3).
A negative index can be used, indicating an offset from the end of the sequence. slice(2,-1) extracts the third element through the second-to-last element in the sequence.
If end is omitted, slice extracts through the end of the sequence (sab.byteLength).

Return value

A new SharedArrayBuffer containing the extracted elements.


var sab = new SharedArrayBuffer(1024);
sab.slice();    // SharedArrayBuffer { byteLength: 1024 }
sab.slice(2);   // SharedArrayBuffer { byteLength: 1022 }
sab.slice(-2);  // SharedArrayBuffer { byteLength: 2 }
sab.slice(0, 1); // SharedArrayBuffer { byteLength: 1 }


Specification Status Comment
ECMAScript Latest Draft (ECMA-262)
The definition of 'SharedArrayBuffer.prototype.slice' in that specification.
Draft Initial definition in ES2017.

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support No support 55 (55) [1] No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support 55.0 (55) [1] No support No support No support

[1] Enabled by default in Firefox 55. In Firefox version 46 until version 54, this feature is disabled by a preference setting (in about:config, set javascript.options.shared_memory to true). 

See also

Document Tags and Contributors

 Contributors to this page: fscholz, chrisdavidmills, roryokane, nmve
 Last updated by: fscholz,