_array-includes.js
947 Bytes
// false -> Array#indexOf
// true -> Array#includes
var toIObject = require('./_to-iobject');
var toLength = require('./_to-length');
var toAbsoluteIndex = require('./_to-absolute-index');
module.exports = function (IS_INCLUDES) {
return function ($this, el, fromIndex) {
var O = toIObject($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) {
if (O[index] === el) return IS_INCLUDES || index || 0;
} return !IS_INCLUDES && -1;
};
};