How Does Prototypal Inheritance Work in JavaScript?

Prototypal Inheritance in JavaScript

Prototypal inheritance is a fundamental concept in JavaScript programming. It allows objects to inherit properties and methods from other objects, creating a hierarchy of related objects.

Understanding the .prototype Property

In JavaScript, every object has a .prototype property that references the prototype object from which it was created. The prototype object contains shared properties and methods that are accessible to all instances of that object.

Instantiating Objects

When you create a new object using new, you're essentially creating an instance of a specific prototype object. This instance inherits all properties and methods from the prototype.

Example:

var obj = new Object();
obj.prototype.test = function() { alert('Hello?'); };
var obj2 = new obj();
obj2.test();

In this example, the obj2 object inherits the test method from the obj prototype object.

The Correct Way

However, the syntax used in the example you provided is incorrect. Instead, you should create a functional object using the function keyword and assign the prototype object to the .prototype property.

function MyObject() {}
MyObject.prototype.test = function() { alert('OK'); };

Conclusion

Prototypal inheritance allows you to define a base object and inherit its functionality and properties into new objects. This mechanism provides a flexible and efficient way to create and manage related objects in JavaScript.

The above is the detailed content of How Does Prototypal Inheritance Work in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!