constructor 屬性返回對建立此對象的 Date 函數的引用。javascript
var a = new Date() //undefined a //Thu Aug 22 2019 15:17:27 GMT+0800 (中國標準時間) a.constructor //ƒ Date() { [native code] } a.constructor == Array //false a.constructor == Boolean //false a.constructor == String //false