finds an item in an array matching a predicate function, and returns its index
npm install find-indexAn implementation of the ES6 method Array.prototype.findIndex as a standalone module and a
ponyfill.
Finds an item in an array matching a predicate function, and returns its index.
Fast both when thisArg is used and also when it isn't.
``bash`
npm install find-index
`js`
var findIndex = require('find-index/findIndex')
var findIndex = require('find-index/ponyfill') // will use native Array#findIndex if available.
var findLastIndex = require('find-index/findLastIndex') // search backwards from end
findIndex(array, callback[, thisArg])
findLastIndex(array, callback[, thisArg])
Parameters:
array
The array to operate on.
callback
Function to execute on each value in the array, taking three arguments:
element
The current element being processed in the array.
index
The index of the current element being processed in the array.
array
The array findIndex was called upon.
thisArg
Object to use as this when executing callback.
Based on array-findindex
`bash
$ iojs --harmony_arrays perf/benchmark.js
native Array.prototype.findIndex: 6347ms
findIndex: 1633ms
findIndex ponyfill: 6384ms
findLastIndex: 1508ms
npm lodash.findindex: 2900ms
npm array-findindex: 3512ms
``