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- var baseIndexOf = require('./_baseIndexOf'),
- isArrayLike = require('./isArrayLike'),
- isString = require('./isString'),
- toInteger = require('./toInteger'),
- values = require('./values');
- /* 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);
- }
- module.exports = includes;
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