The Object.getOwnPropertyDescriptors()
method returns the property descriptors for all the properties of the given object.
Example
let obj = {
value: 11,
get number() {
return this.value;
},
};
// get property descriptors for all the properties of obj
let objectProperties = Object.getOwnPropertyDescriptors(obj);
console.log(objectProperties);
Output
{ value: { value: 11, writable: true, enumerable: true, configurable: true }, number: { get: [Function: get number], set: undefined, enumerable: true, configurable: true } }
getOwnPropertyDescriptors() Syntax
The syntax of the getOwnPropertyDescriptors()
method is:
Object.getOwnPropertyDescriptors(obj)
Here, getOwnPropertyDescriptors()
is a static method. Hence, we need to access the method using the class name, Object
.
getOwnPropertyDescriptors() Parameters
The getOwnPropertyDescriptors()
method takes in:
- obj - the object whose property descriptors we require.
getOwnPropertyDescriptors() Return Value
The getOwnPropertyDescriptors()
method returns an object containing all the property descriptors of the given object.
Example 1: JavaScript Object.getOwnPropertyDescriptors()
let obj = {
x: 10,
get number() {
return this.x;
},
};
// get the property descriptors for all the properties of obj
let value = Object.getOwnPropertyDescriptors(obj);
console.log(value);
Output
{ x: { value: 10, writable: true, enumerable: true, configurable: true }, number: { get: [Function: get number], set: undefined, enumerable: true, configurable: true } }
In the above example, the obj object contains the following properties:
- x - a property with a value of 10.
number()
- a getter method named which returns the value of x.
We then used the Object.getOwnPropertyDescriptors()
method to get the descriptors for all the properties of obj i.e. x and number()
.
Example 2: getOwnPropertyDescriptors() for Shallow Copy
let obj = {
x: 10,
get number() {
return this.x;
},
};
// use getOwnPropertyDescriptors() for shallow copy
let cloneObj = Object.create(
Object.getPrototypeOf(obj),
Object.getOwnPropertyDescriptors(obj)
);
console.log(cloneObj);
// Output: { x: 10, number: [Getter] }
In the above example, we can see that the getOwnPropertyDescriptors()
method along with the create()
method can help us create a shallow copy.
To demonstrate this, we first created an object named obj with the properties:
- x - a property with the value 10.
number()
- a getter method that returns the value of x.
Then, we created a shallow copy of obj (called cloneObj) using the create()
, getPrototypeOf()
, and getOwnPropertyDescriptors()
methods.
let cloneObj = Object.create(
Object.getPrototypeOf(obj),
Object.getOwnPropertyDescriptors(obj)
);
As shown by the output, cloneObj is a shallow copy of obj since both objects are the same (they point to the same memory address).
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