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array-includes.js
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array-includes.js
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var toIndexedObject = require('../internals/to-indexed-object');
var toLength = require('../internals/to-length');
var toAbsoluteIndex = require('../internals/to-absolute-index');
// `Array.prototype.{ indexOf, includes }` methods implementation
var createMethod = function (IS_INCLUDES) {
return function ($this, el, fromIndex) {
var O = toIndexedObject($this);
var length = toLength(O.length);
var index = toAbsoluteIndex(fromIndex, length);
var value;
// Array#includes uses SameValueZero equality algorithm
// eslint-disable-next-line no-self-compare
if (IS_INCLUDES && el != el) while (length > index) {
value = O[index++];
// eslint-disable-next-line no-self-compare
if (value != value) return true;
// Array#indexOf ignores holes, Array#includes - not
} else for (;length > index; index++) {
if ((IS_INCLUDES || index in O) && O[index] === el) return IS_INCLUDES || index || 0;
} return !IS_INCLUDES && -1;
};
};
module.exports = {
// `Array.prototype.includes` method
// https://tc39.es/ecma262/#sec-array.prototype.includes
includes: createMethod(true),
// `Array.prototype.indexOf` method
// https://tc39.es/ecma262/#sec-array.prototype.indexof
indexOf: createMethod(false)
};