How can I modify the Object constructor
When I run the following code
var ExtendedObject = function() {
this.standard = 5;
};
Object = ExtendedObject.bind(Object);
var p = new Object();
console.dir(p.standard);
, the output is
5
as expected.
If I instead instantiate the variable p as an object literal like this:
var ExtendedObject = function() {
this.standard = 5;
};
Object = ExtendedObject.bind(Object);
var p = {};
console.dir(p.standard);
The result is
undefined
I am trying to find a way to modify the constructor of Object such that I can add some standard content to all new objects being created.
No, it is absolutely impossible to redefine how an object literal evaluates; it will always become a native object with the builtin Object.prototype , not a subclass or anything and it will also not invoke a custom constructor.
This is in fact a security feature, as it prevents JSON hijacking.
… such that I can add some standard content to all new objects being created
That's a horrible idea and will break every library you'd ever use in this environment (including all functions you'd write yourself). However, if you insist on having a common (not individual!) property on all objects, you might consider defining it on Object.prototype . Not that I would recommend it, but at least do it correctly.
您可以创建一个类并从Object扩展它。
class MyObject extends Object {
constructor() {
super();
this.standard = 5;
}
}
const obj = new MyObject();
console.log(obj);在Object的原型上定义属性，如下所示：
Object.defineProperty(Object.prototype, 'standard', {
value: 5,
writable: true,
enumerable: true,
configurable: true
});
var p = {};
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