package.internals.array-last-index-of.js Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of core-js-pure Show documentation

Standard library

The newest version!

'use strict';
/* eslint-disable es/no-array-prototype-lastindexof -- safe */
var apply = require('../internals/function-apply');
var toIndexedObject = require('../internals/to-indexed-object');
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
var lengthOfArrayLike = require('../internals/length-of-array-like');
var arrayMethodIsStrict = require('../internals/array-method-is-strict');

var min = Math.min;
var $lastIndexOf = [].lastIndexOf;
var NEGATIVE_ZERO = !!$lastIndexOf && 1 / [1].lastIndexOf(1, -0) < 0;
var STRICT_METHOD = arrayMethodIsStrict('lastIndexOf');
var FORCED = NEGATIVE_ZERO || !STRICT_METHOD;

// `Array.prototype.lastIndexOf` method implementation
// https://tc39.es/ecma262/#sec-array.prototype.lastindexof
module.exports = FORCED ? function lastIndexOf(searchElement /* , fromIndex = @[*-1] */) {
  // convert -0 to +0
  if (NEGATIVE_ZERO) return apply($lastIndexOf, this, arguments) || 0;
  var O = toIndexedObject(this);
  var length = lengthOfArrayLike(O);
  if (length === 0) return -1;
  var index = length - 1;
  if (arguments.length > 1) index = min(index, toIntegerOrInfinity(arguments[1]));
  if (index < 0) index = length + index;
  for (;index >= 0; index--) if (index in O && O[index] === searchElement) return index || 0;
  return -1;
} : $lastIndexOf;