aaac7fed
 liuqimichale
add
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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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