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77 lines
2.0 KiB
77 lines
2.0 KiB
var baseKeys = require('./_baseKeys'), |
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getTag = require('./_getTag'), |
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isArguments = require('./isArguments'), |
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isArray = require('./isArray'), |
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isArrayLike = require('./isArrayLike'), |
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isBuffer = require('./isBuffer'), |
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isPrototype = require('./_isPrototype'), |
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isTypedArray = require('./isTypedArray'); |
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/** `Object#toString` result references. */ |
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var mapTag = '[object Map]', |
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setTag = '[object Set]'; |
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/** Used for built-in method references. */ |
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var objectProto = Object.prototype; |
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/** Used to check objects for own properties. */ |
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var hasOwnProperty = objectProto.hasOwnProperty; |
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/** |
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* Checks if `value` is an empty object, collection, map, or set. |
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* |
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* Objects are considered empty if they have no own enumerable string keyed |
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* properties. |
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* |
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* Array-like values such as `arguments` objects, arrays, buffers, strings, or |
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* jQuery-like collections are considered empty if they have a `length` of `0`. |
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* Similarly, maps and sets are considered empty if they have a `size` of `0`. |
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* |
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* @static |
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* @memberOf _ |
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* @since 0.1.0 |
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* @category Lang |
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* @param {*} value The value to check. |
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* @returns {boolean} Returns `true` if `value` is empty, else `false`. |
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* @example |
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* |
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* _.isEmpty(null); |
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* // => true |
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* |
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* _.isEmpty(true); |
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* // => true |
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* |
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* _.isEmpty(1); |
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* // => true |
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* |
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* _.isEmpty([1, 2, 3]); |
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* // => false |
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* |
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* _.isEmpty({ 'a': 1 }); |
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* // => false |
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*/ |
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function isEmpty(value) { |
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if (value == null) { |
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return true; |
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} |
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if (isArrayLike(value) && |
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(isArray(value) || typeof value == 'string' || typeof value.splice == 'function' || |
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isBuffer(value) || isTypedArray(value) || isArguments(value))) { |
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return !value.length; |
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} |
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var tag = getTag(value); |
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if (tag == mapTag || tag == setTag) { |
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return !value.size; |
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} |
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if (isPrototype(value)) { |
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return !baseKeys(value).length; |
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} |
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for (var key in value) { |
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if (hasOwnProperty.call(value, key)) { |
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return false; |
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} |
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} |
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return true; |
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} |
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module.exports = isEmpty;
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