Welcome to JavaScript inheritance! Inheritance is a fundamental concept that allows objects to inherit properties and methods from other objects. Unlike classical object-oriented languages, JavaScript uses prototype-based inheritance, which provides flexibility and code reuse through object relationships.
The prototype chain is the core mechanism of JavaScript inheritance. Every object has a hidden prototype property that points to another object. When you access a property, JavaScript first checks the object itself, then its prototype, then the prototype's prototype, continuing up the chain until the property is found or the chain ends at null.
Before ES6 classes, JavaScript inheritance was implemented using constructor functions. This involved creating constructor functions for parent and child objects, setting up prototype relationships using Object dot create, and calling the parent constructor with the call method. While functional, this approach was verbose and less intuitive for developers coming from classical object-oriented languages.
ES6 introduced the class syntax, which provides a cleaner and more familiar way to implement inheritance. The extends keyword creates inheritance relationships, while super is used to call the parent constructor and methods. This syntax is syntactic sugar over JavaScript's existing prototype-based inheritance, making it more accessible to developers from classical object-oriented backgrounds.
To summarize JavaScript inheritance: JavaScript uses prototype-based inheritance where objects inherit through the prototype chain. While traditional constructor functions work, ES6 classes provide cleaner syntax with extends and super keywords. Both approaches enable code reuse and object relationships, ultimately implementing the same prototype-based inheritance mechanism that makes JavaScript flexible and powerful.