JavaScript

Prototype

Definition

Every JavaScript object has a hidden internal property called `[[Prototype]]` that links to another object. When a property is accessed on an object and not found, JavaScript walks up the prototype chain to find it. This is the basis of JavaScript's inheritance model.

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Related Terms

Class

ES6 syntactic sugar over JavaScript's prototype-based inheritance. Classes provide a cleaner way to create objects and implement inheritance using extends and super.

This Keyword

A special keyword that refers to the object a function is called on. Its value depends on how a function is invoked: in a method, this refers to the owner object; in a regular function, it defaults to globalThis (or undefined in strict mode).

Inheritance

A mechanism where a class (child) derives properties and methods from another class (parent). In JavaScript, inheritance is achieved through the prototype chain or the extends keyword with ES6 classes.