The find() method returns a value in the typed array, if an element satisfies the provided testing function. Otherwise undefined is returned. TypedArray is one of the typed array types here.

See also the findIndex() method, which returns the index of a found element in the typed array instead of its value.


<var>typedarray</var>.find(<var>callback</var>[, <var>thisArg</var>])


Function to execute on each value in the typed array, taking three arguments:
The current element being processed in the typed array.
The index of the current element being processed in the typed array.
The array find was called upon.
Optional. Object to use as this when executing callback.

Return value

A value in the array if an element passes the test; otherwise, undefined.


The find method executes the callback function once for each element present in the typed array until it finds one where callback returns a true value. If such an element is found, find immediately returns the value of that element. Otherwise, find returns undefined. callback is invoked only for indexes of the typed array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

callback is invoked with three arguments: the value of the element, the index of the element, and the typed array object being traversed.

If a thisArg parameter is provided to find, it will be used as the this for each invocation of the callback. If it is not provided, then undefined is used.

find does not mutate the typed array on which it is called.

The range of elements processed by find is set before the first invocation of callback. Elements that are appended to the typed array after the call to find begins will not be visited by callback. If an existing, unvisited element of the typed array is changed by callback, its value passed to the visiting callback will be the value at the time that find visits that element's index; elements that are deleted are not visited.


Find a prime number in a typed array

The following example finds an element in the typed array that is a prime number (or returns undefined if there is no prime number).

function isPrime(element, index, array) {
  var start = 2;
  while (start <= Math.sqrt(element)) {
    if (element % start++ < 1) {
      return false;
  return element > 1;

var uint8 = new Uint8Array([4, 5, 8, 12]);
console.log(uint8.find(isPrime)); // 5


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of '%TypedArray%.prototype.find' in that specification.
Standard Initial definition.
ECMAScript 2017 Draft (ECMA-262)
The definition of '%TypedArray%.prototype.find' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support 37.0 (37.0) 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 37.0 (37.0) No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

ECMAScript6 JavaScript Method Prototype Reference TypedArray TypedArrays