.getOwnPropertyNames()

The .getOwnPropertyNames() method returns all properties that are present in a given object except for those symbol-based non-enumerable properties.

Syntax

Object.getOwnPropertyNames(obj)

• obj: This parameter holds the object whose enumerable and non-enumerable properties are to be returned.

Examples

Example 1

In this example, Object.getOwnPropertyNames() returns an array containing the property names of the person object:

const person = {
  firstName: 'Jane',
  lastName: 'Doe',
  age: 40,
};

const propertyNames = Object.getOwnPropertyNames(person);
console.log(propertyNames);

The above example will return the following output:

['firstName', 'lastName', 'age']

Example 2

In this example, the obj object has both enumerable and non-enumerable properties. Object.getOwnPropertyNames() includes both types of properties in the resulting array:

const obj = Object.create(
  {},
  {
    nonEnumerableProp: {
      value: 'I am non-enumerable',
      enumerable: false,
    },
    enumerableProp: {
      value: 'I am enumerable',
      enumerable: true,
    },
  }
);

const propertyNames = Object.getOwnPropertyNames(obj);
console.log(propertyNames);

The above example will return the following output:

['nonEnumerableProp', 'enumerableProp']