hasOwnProperty()和in操作符的区别

1、hasOwnProperty 只能检测对象实例属性&＃xff0c;无法检测原型中的属性

2、in 只要能访问到的属性都可以检测到

举个栗子&＃xff1a;

class Box{constructor(num1,num2){this.num1 &＃61; num1;this.num2&＃61;num2;}sum(){return num1&＃43;num2;}
}
var box&＃61;new Box(12,88);
console.log(box.hasOwnProperty("num1"));//true
console.log(box.hasOwnProperty("num2"));//true
console.log(box.hasOwnProperty("sum"));//false
console.log("num1" in box);//true
console.log("num2" in box);//true
console.log("sum" in box);//true
console.log("say" in box);//false