| var baseIndexOf = require('../internal/baseIndexOf'), |
| getLength = require('../internal/getLength'), |
| isArray = require('../lang/isArray'), |
| isIterateeCall = require('../internal/isIterateeCall'), |
| isLength = require('../internal/isLength'), |
| isString = require('../lang/isString'), |
| values = require('../object/values'); |
| |
| /* Native method references for those with the same name as other `lodash` methods. */ |
| var nativeMax = Math.max; |
| |
| /** |
| * Checks if `target` is in `collection` using |
| * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) |
| * for equality comparisons. If `fromIndex` is negative, it's used as the offset |
| * from the end of `collection`. |
| * |
| * @static |
| * @memberOf _ |
| * @alias contains, include |
| * @category Collection |
| * @param {Array|Object|string} collection The collection to search. |
| * @param {*} target The value to search for. |
| * @param {number} [fromIndex=0] The index to search from. |
| * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`. |
| * @returns {boolean} Returns `true` if a matching element is found, else `false`. |
| * @example |
| * |
| * _.includes([1, 2, 3], 1); |
| * // => true |
| * |
| * _.includes([1, 2, 3], 1, 2); |
| * // => false |
| * |
| * _.includes({ 'user': 'fred', 'age': 40 }, 'fred'); |
| * // => true |
| * |
| * _.includes('pebbles', 'eb'); |
| * // => true |
| */ |
| function includes(collection, target, fromIndex, guard) { |
| var length = collection ? getLength(collection) : 0; |
| if (!isLength(length)) { |
| collection = values(collection); |
| length = collection.length; |
| } |
| if (typeof fromIndex != 'number' || (guard && isIterateeCall(target, fromIndex, guard))) { |
| fromIndex = 0; |
| } else { |
| fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0); |
| } |
| return (typeof collection == 'string' || !isArray(collection) && isString(collection)) |
| ? (fromIndex <= length && collection.indexOf(target, fromIndex) > -1) |
| : (!!length && baseIndexOf(collection, target, fromIndex) > -1); |
| } |
| |
| module.exports = includes; |