import baseIndexOf from './_baseIndexOf.js'; import isArrayLike from './isArrayLike.js'; import isString from './isString.js'; import toInteger from './toInteger.js'; import values from './values.js'; /* Built-in method references for those with the same name as other `lodash` methods. */ var nativeMax = Math.max; /** * Checks if `value` is in `collection`. If `collection` is a string, it's * checked for a substring of `value`, otherwise * [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero) * is used for equality comparisons. If `fromIndex` is negative, it's used as * the offset from the end of `collection`. * * @static * @memberOf _ * @since 0.1.0 * @category Collection * @param {Array|Object|string} collection The collection to inspect. * @param {*} value The value to search for. * @param {number} [fromIndex=0] The index to search from. * @param- {Object} [guard] Enables use as an iteratee for methods like `_.reduce`. * @returns {boolean} Returns `true` if `value` is found, else `false`. * @example * * _.includes([1, 2, 3], 1); * // => true * * _.includes([1, 2, 3], 1, 2); * // => false * * _.includes({ 'a': 1, 'b': 2 }, 1); * // => true * * _.includes('abcd', 'bc'); * // => true */ function includes(collection, value, fromIndex, guard) { collection = isArrayLike(collection) ? collection : values(collection); fromIndex = (fromIndex && !guard) ? toInteger(fromIndex) : 0; var length = collection.length; if (fromIndex < 0) { fromIndex = nativeMax(length + fromIndex, 0); } return isString(collection) ? (fromIndex <= length && collection.indexOf(value, fromIndex) > -1) : (!!length && baseIndexOf(collection, value, fromIndex) > -1); } export default includes;