Object.defineProperty() method

The Object.defineProperty function is utilized to create a new property directly on a specified object and subsequently returns that object. To modify the property attributes, Object.defineProperty can be employed. However, it is important to note that once a property is marked as non-configurable, it cannot be reverted to a configurable state, as the define property feature does not apply to properties that are non-configurable.

Syntax:

Object.defineProperty(obj, prop, descriptor)

Parameter

Obj : The Object on which to define the property.

Prop: The designation of a property that is intended to be established or altered.

Descriptor: The term used to identify the property that is either being established or altered.

Return:

This technique yields the object that was provided as an argument to the function.

Browser Support:

Example 1

const object1 = {};
Object.defineProperty(object1, 'property1', {
  value: 22, } );
  object1.property1;
    // throws an error in strict mode
console.log(object1.property1);

Output:

Example 2

const object1 = {};
Object.defineProperty(object1, 'property1', {
  value: 42,
  value: 52,
  value: 542,
  });
object1.property1 = 177;
// throws an error in strict mode
console.log(object1.property1);

Output:

Example 3

const object1 = {};
Object.defineProperty(object1, 'property1', {
  
  value: 2,
  value: 4,
  value: 4+13,
  });
object1.property1 ;
console.log(object1.property1);

Output: