30秒学会 JavaScript 片段 – Collection is empty

Checks if the a value is an empty object/collection, has no enumerable properties or is any type that is not considered a collection.

• Check if the provided value is null or if its length is equal to 0.

代码实现

const isEmpty = val => val == null || !(Object.keys(val) || val).length;

isEmpty([]); // true
isEmpty({}); // true
isEmpty(''); // true
isEmpty([1, 2]); // false
isEmpty({ a: 1, b: 2 }); // false
isEmpty('text'); // false
isEmpty(123); // true - type is not considered a collection
isEmpty(true); // true - type is not considered a collection

翻译自：https://www.30secondsofcode.org/js/s/collection-is-empty