JavaScript对象getOwnPropertyDescriptors()

The getOwnPropertyDescriptors() method is a feature in JavaScript that helps to retrieve all the own property descriptors of an object. This includes all getters, setters, and properties that are configurable, enumerable, and writable.

Syntax

Object.getOwnPropertyDescriptors(obj)

Parameters

• obj: The object for which to get the property descriptors.

Return Value

This method returns an object containing all of the property descriptors for the specified object.

Example

const car = {
  make: 'Toyota',
  model: 'Camry',
  year: 2019,
  get makeModel() {
    return this.make + ' ' + this.model;
  },
};

const descriptors = Object.getOwnPropertyDescriptors(car);

console.log(descriptors);
/*
{
  make: {
    value: 'Toyota',
    writable: true,
    enumerable: true,
    configurable: true
  },
  model: {
    value: 'Camry',
    writable: true,
    enumerable: true,
    configurable: true
  },
  year: {
    value: 2019,
    writable: true,
    enumerable: true,
    configurable: true
  },
  makeModel: {
    get: [Function: get makeModel],
    set: undefined,
    enumerable: true,
    configurable: true
  }
}
*/

In this example, we first define an object called car with several properties and a getter method. Then, we use the Object.getOwnPropertyDescriptors() method to retrieve all of the property descriptors for the specified car object. The resulting object contains descriptors for all of the properties, including the makeModel getter.

Compatibility

The getOwnPropertyDescriptors() method is part of the ECMAScript 2017 specification and is supported in most modern browsers. However, it may not be supported in older browsers or environments that do not support ECMAScript 2017.

Conclusion

The getOwnPropertyDescriptors() method is a powerful tool for working with objects in JavaScript. By using this method, you can retrieve detailed information about an object's properties, including getters, setters, and other descriptors. This can be very useful for debugging and other advanced programming tasks.