三组数据对比:
typeof * | *.length | isNaN(*.length) | Object.prototype.toString.call(*) | Array.isArray(*) | *.constructor | * instanceof Array | |
arr1 | object | 7 | false | [object Array] | true | ? Array() { [native code] } | true |
newArr | object | undefined | true | [object Set] | false | ? Set() { [native code] } | false |
newObj | object | undefined | true | [object Object] | false | ? Object() { [native code] } | false |
原文:https://www.cnblogs.com/simpleyou/p/14623098.html