javascript delete prototype

JavaScript is a powerful scripting language with rich syntax and features. Prototype is an important concept in JavaScript. Prototype is a mechanism in JavaScript that supports object inheritance. It is a special object that can be used as a default property when creating an object. The use of prototypes makes it easier to inherit and reuse objects, so it is a concept that must be mastered in JavaScript. However, sometimes we need to delete the prototype, what should we do at this time? This article will detail how to delete prototypes in JavaScript.

1. What is a prototype

In JavaScript, everything is an object. When we create an object, it automatically inherits an object called prototype, which is a built-in object in JavaScript. We can think of a prototype as a template that defines the properties and methods owned by an object. For example, when we create a Dog object, it will automatically inherit a prototype object, which contains all the common properties and methods of Dog objects, such as name, sound, bark, etc.

2. How to delete the prototype

Sometimes, we need to delete the prototype. For example, we don’t want an object to inherit any properties and methods, or we want to rename an object. Setting up prototypes, etc. So, how do you delete a prototype? Two methods are introduced below:

Method 1: Use the Object.setPrototypeOf() method

The Object.setPrototypeOf() method is used to set the prototype of an object to another object or null. When we set the prototype to null, it is equivalent to deleting the prototype. The following is an example:

let Dog = function(name) {
    this.name = name;
};

let dog = new Dog('小狗');
console.log(Dog.prototype); // {constructor: ƒ}
console.log(dog.__proto__); // {constructor: ƒ}

Object.setPrototypeOf(dog, null);
console.log(Dog.prototype); // {constructor: ƒ}
console.log(dog.__proto__); // null

In the above example, we called the Object.setPrototypeOf() method to set the prototype of the dog object to null, which is equivalent to deleting the prototype. At this point, we can find that the value of dog.__proto__ is null.

Method 2: Use delete keyword

In addition to using the Object.setPrototypeOf() method, we can also use the delete keyword in JavaScript to delete the prototype, for example:

let Dog = function(name) {
    this.name = name;
};

let dog = new Dog('小狗');
console.log(Dog.prototype); // {constructor: ƒ}
console.log(dog.__proto__); // {constructor: ƒ}

delete dog.__proto__;
console.log(Dog.prototype); // {constructor: ƒ}
console.log(dog.__proto__); // undefined

In the above example, we use the delete keyword to delete the prototype of the dog object. At this time, we can find that the value of dog.__proto__ is undefined.

3. Summary

The prototype in JavaScript is an important mechanism for object inheritance. It is a special object that contains properties and methods. In some cases, we need to delete the prototype, which can be achieved using the Object.setPrototypeOf() method or the delete keyword. It should be noted that deleting the prototype may have a certain impact on code inheritance and reuse, so it needs to be used with caution.

The above is the detailed content of javascript delete prototype. For more information, please follow other related articles on the PHP Chinese website!