blob: 3401db3fce2ef81882178cb388d43b739062038b [file] [log] [blame]
'use strict';
var toIndexedObject = require('../internals/to-indexed-object');
var toInteger = require('../internals/to-integer');
var toLength = require('../internals/to-length');
var sloppyArrayMethod = require('../internals/sloppy-array-method');
var min = Math.min;
var nativeLastIndexOf = [].lastIndexOf;
var NEGATIVE_ZERO = !!nativeLastIndexOf && 1 / [1].lastIndexOf(1, -0) < 0;
var SLOPPY_METHOD = sloppyArrayMethod('lastIndexOf');
// `Array.prototype.lastIndexOf` method implementation
// https://tc39.github.io/ecma262/#sec-array.prototype.lastindexof
module.exports = (NEGATIVE_ZERO || SLOPPY_METHOD) ? function lastIndexOf(searchElement /* , fromIndex = @[*-1] */) {
// convert -0 to +0
if (NEGATIVE_ZERO) return nativeLastIndexOf.apply(this, arguments) || 0;
var O = toIndexedObject(this);
var length = toLength(O.length);
var index = length - 1;
if (arguments.length > 1) index = min(index, toInteger(arguments[1]));
if (index < 0) index = length + index;
for (;index >= 0; index--) if (index in O && O[index] === searchElement) return index || 0;
return -1;
} : nativeLastIndexOf;