TypedArray.prototype.slice()

The slice() method returns a shallow copy of a portion of a typed array into a new typed array object. This method has the same algorithm as Array.prototype.slice(). TypedArray is one of the typed array types here.

Syntax

typedarray.slice([begin[, end]])

Parameters

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 (typedarray.length).

Return value

A new typed array containing the extracted elements.

Description

The slice method does not alter. It returns a shallow copy of elements from the original typed array.

If a new element is added to either typed array, the other typed array is not affected.

Examples

Return a portion of an existing typed array

const uint8 = new Uint8Array([1,2,3]);
uint8.slice(1);   // Uint8Array [ 2, 3 ]
uint8.slice(2);   // Uint8Array [ 3 ]
uint8.slice(-2);  // Uint8Array [ 2, 3 ]
uint8.slice(0,1); // Uint8Array [ 1 ]

Polyfill

Since there is no global object with the name TypedArray, polyfilling must be done on an "as needed" basis.

if (!Uint8Array.prototype.slice) {
  Object.defineProperty(Uint8Array.prototype, 'slice', {
    value: function (begin, end)
     {
        return new Uint8Array(Array.prototype.slice.call(this, begin, end));
     }
  });
}

If you need to support truly obsolete JavaScript engines that don't support Object.defineProperty, it's best not to polyfill Array.prototype methods at all, as you can't make them non-enumerable.

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of '%TypedArray%.prototype.slice' in that specification.		 Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of '%TypedArray%.prototype.slice' in that specification.		 Draft

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
sliceChrome Full support 45Edge Full support 14Firefox Full support 38IE No support NoOpera Full support 32Safari ? WebView Android Full support 45Chrome Android Full support 45Firefox Android Full support 38Opera Android ? Safari iOS ? Samsung Internet Android Full support 5.0nodejs Full support 4.0.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown

See also

Related Topics
  1. Standard built-in objects
  2. TypedArray
  3. Properties
    1. TypedArray.BYTES_PER_ELEMENT
    2. TypedArray.name
    3. TypedArray.prototype
    4. TypedArray.prototype.buffer
    5. TypedArray.prototype.byteLength
    6. TypedArray.prototype.byteOffset
    7. TypedArray.prototype.length
    8. get TypedArray[@@species]
  4. Methods
    1. TypedArray.from()
    2. TypedArray.of()
    3. TypedArray.prototype.copyWithin()
    4. TypedArray.prototype.entries()
    5. TypedArray.prototype.every()
    6. TypedArray.prototype.fill()
    7. TypedArray.prototype.filter()
    8. TypedArray.prototype.find()
    9. TypedArray.prototype.findIndex()
    10. TypedArray.prototype.forEach()
    11. TypedArray.prototype.includes()
    12. TypedArray.prototype.indexOf()
    13. TypedArray.prototype.join()
    14. TypedArray.prototype.keys()
    15. TypedArray.prototype.lastIndexOf()
    16. TypedArray.prototype.map()
    17. TypedArray.prototype.move()
    18. TypedArray.prototype.reduce()
    19. TypedArray.prototype.reduceRight()
    20. TypedArray.prototype.reverse()
    21. TypedArray.prototype.set()
    22. TypedArray.prototype.slice()
    23. TypedArray.prototype.some()
    24. TypedArray.prototype.sort()
    25. TypedArray.prototype.subarray()
    26. TypedArray.prototype.toLocaleString()
    27. TypedArray.prototype.toString()
    28. TypedArray.prototype.values()
    29. TypedArray.prototype[@@iterator]()
  5. Related pages:
  6. Int8Array
  7. Uint8Array
  8. Uint8ClampedArray
  9. Int16Array
  10. Uint16Array
  11. Int32Array
  12. Uint32Array
  13. Float32Array
  14. Float64Array
  15. BigInt64Array
  16. BigUint64Array
  17. Inheritance:
  18. Function
  19. Properties
    1. Function.arguments
    2. Function.arity
    3. Function.caller
    4. Function.displayName
    5. Function.length
    6. Function.name
    7. Function.prototype
  20. Methods
    1. Function.prototype.apply()
    2. Function.prototype.bind()
    3. Function.prototype.call()
    4. Function.prototype.isGenerator()
    5. Function.prototype.toSource()
    6. Function.prototype.toString()
  21. Object
  22. Properties
    1. Object.prototype.__count__
    2. Object.prototype.__noSuchMethod__
    3. Object.prototype.__parent__
    4. Object.prototype.__proto__
    5. Object.prototype.constructor
  23. Methods
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.unwatch()
    12. Object.prototype.valueOf()
    13. Object.prototype.watch()
    14. Object.setPrototypeOf()