为什么我无法从对象实例中删除getter函数

Question

我很困惑为什么我不能从构造函数的对象实例中删除getter函数：

//created constructor function
let f = function () {
this.a = 1;
this.b = 2;   
}

//created an instance
let o = new f()

//created a getter function on object o
Object.defineProperties(o, {f: 
{get: function(){
return 100
}
}})

//tried to delete but got response as false.
delete o.f

Answer 1

您只能删除可配置的属性。来自MDN:

configurable
true如果此属性描述符的类型可以更改，并且属性可以从相应对象中删除。默认为false。

//created constructor function
let f = function () {
this.a = 1;
this.b = 2;   
}

//created an instance
let o = new f()

//created a getter function on object o
Object.defineProperties(o, {
f: {
get: function(){
return 100
},
configurable: true,
}
})
console.log(delete o.f);

Answer 2

这是因为您没有将f属性设置为configurable:

//created constructor function
let f = function () {
this.a = 1;
this.b = 2;   
}

//created an instance
let o = new f()

//created a getter function on object o
Object.defineProperties(o, {
f: {
get: function(){
return 100
},
configurable: true
}
});

//tried to delete but got response as false.
console.log(delete o.f);
console.log(o.f);