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- 'use strict';
- var toIndexedObject = require('../internals/to-indexed-object');
- var toInteger = require('../internals/to-integer');
- var toLength = require('../internals/to-length');
- var arrayMethodIsStrict = require('../internals/array-method-is-strict');
- var arrayMethodUsesToLength = require('../internals/array-method-uses-to-length');
- var min = Math.min;
- var nativeLastIndexOf = [].lastIndexOf;
- var NEGATIVE_ZERO = !!nativeLastIndexOf && 1 / [1].lastIndexOf(1, -0) < 0;
- var STRICT_METHOD = arrayMethodIsStrict('lastIndexOf');
- // For preventing possible almost infinite loop in non-standard implementations, test the forward version of the method
- var USES_TO_LENGTH = arrayMethodUsesToLength('indexOf', { ACCESSORS: true, 1: 0 });
- var FORCED = NEGATIVE_ZERO || !STRICT_METHOD || !USES_TO_LENGTH;
- // `Array.prototype.lastIndexOf` method implementation
- // https://tc39.github.io/ecma262/#sec-array.prototype.lastindexof
- module.exports = FORCED ? 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;
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