VietMX Staff asked 3 years ago
JavaScript is a prototype-based language: there are no classes and objects are created by using a cloning process. JavaScript is also dynamically typed: types and type informations are not explicit and properties can be added to and deleted from objects on the fly.
Accessing types and properties effectively makes a first big challenge for V8. Instead of using a dictionary-like data structure for storing object properties and doing a dynamic lookup to resolve the property location (like most JavaScript engines do), V8 creates hidden classes, at runtime, in order to have an internal representation of the type system and to improve the property access time.
