JavaScript Object defineProperty() Method (original) (raw)

Last Updated : 12 Jul, 2024

The **Object.defineProperty() method in JavaScript is a Standard built-in object which defines a new property directly on an object or it can also modify the existing property of an object and return the object.

**Syntax:

Object.defineProperty(obj, prop, descriptor)

**Parameters:

This method accepts three parameters as mentioned above and described below:

• **Obj: This parameter holds the Object on which the user is going to define the property.
• **Prop: This parameter holds the name of a property that is going to be defined or modified.
• **Descriptor: This parameter holds the descriptor for the property being defined or modified.

**Return Value:

• This method returns the object which is passed as the argument to the function.

**Example 1: In this example, we will add new properties to an object and print it in the console using the Object.defineProperty() method in JavaScript.

javascript `

const geek1 = {}; Object.defineProperty(geek1, 'prop1', { value: 65, writable: false }); geek1.prop1 = 7; console.log(geek1.prop1);

const geek2 = {}; Object.defineProperty(geek2, 'prop2', {

value: 54,
value: 23,
value: 12 * 9,

}); geek2.prop2; console.log(geek2.prop2);

`

**Output:

65
108

**Example 2: In this example, we will add new properties to an object and print it in the console using the Object.defineProperty() method in JavaScript.

javascript `

function gfg() { }

let result; Object.defineProperty(gfg.prototype, "valx", { get() { return result; }, set(valx) { result = valx; } });

let vala = new gfg(); let valb = new gfg(); vala.valx = 6; console.log(valb.valx);

function gfg1() { }

gfg1.prototype.valx = 4; Object.defineProperty(gfg1.prototype, "valy", { writable: false, value: 8 });

let vala = new gfg1(); vala.valx = 4; console.log(vala.valx); console.log(gfg1.prototype.valx); vala.valy = 2; console.log(vala.valy); console.log(gfg1.prototype.valy);

`

**Output:

6
4
4
8
8

We have a complete list of Javascript Object methods, to check those please go through this JavaScript Object Complete Reference article.

**Supported Browsers:

The browsers supported by Object.defineProperty() method are listed below:

• Google Chrome
• Firefox
• Opera
• Safari
• Edge