JavaScript Object setPrototypeOf() Method

The Object.setPrototypeOf() method in JavaScript is a standard built-in object which sets the prototype (i.e., the internal [[Prototype]] property) of a specified object to another object or null.

Syntax:

Object.setPrototypeOf(obj, prototype)

Parameters: This method accepts two parameters as mentioned above and described below: 

• obj: This parameter is the object which is going to have its prototype set.
• Prototype: This parameter is the object’s new prototype. It can be an object or a null object.

Return value: This method returns the specified object.

The below examples illustrate the Object.setPrototypeOf() Method in JavaScript:

Example 1: In this example, we will set a prototype of an object using the Object.setPrototypeOf() Method in JavaScript.

javascript

let geek1 = {
    prop1() {
        return 'Object.isExtensible()';
    },
    prop2() {
        return 'JavaScript ';
    }
}
let geek2 = {
    prop3() {
        return 'Geeksforgeeks';
    }
}

Object.setPrototypeOf(geek2, geek1);

console.dir(geek2);
console.log(geek2.prop3());
console.log(geek2.prop2());
console.log(geek2.prop1());

Output:

"Geeksforgeeks"
"JavaScript "
"Object.isExtensible()"

Example 2: In this example, we will set a prototype of an object using the Object.setPrototypeOf() Method in JavaScript.

javascript

let geeks1 = {
    prop1() {
        console.log(this.name + ' is Best platform');
    },
    prop2() {
        console.log(this.name + ' provide jobs opportunity');
    }
};

class geeks2 {
    constructor(name) {
        this.name = name;
    }
}

Object.setPrototypeOf(geeks2.prototype, geeks1);
let result = new geeks2('GeeksforGeeks');
result.prop1();
result.prop2();

Output:

"GeeksforGeeks is Best platform"
"GeeksforGeeks provide jobs opportunity"

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.setPrototypeOf() method are listed below: 

• Google Chrome 34 and above
• Edge 12 and above
• Firefox 31 and above
• Opera 21 and above
• Safari 9 and above