JavaScript Prototypes

• Description
• Syntax
• Object.prototype
• Footnotes

Description

A prototype can be seen as an [JavaScript Objects](JavaScript Objects) another object extends.

Syntax

let protoRabbit = {
  speak(line) {
    console.log(`The ${this.type} rabbit says '${line}'`); // : The killer rabbit says 'SKREEEE!'
  },
};
let killerRabbit = Object.create(protoRabbit);
killerRabbit.type = "killer";
killerRabbit.speak("SKREEEE!");

Object.prototype

Most objects in JavaScript eventually extend Object.prototype through parent prototype objects or directly, which provides a bunch of default methods[fn:defaultmethods].

console.log(Object.getPrototypeOf({}) == Object.prototype); // true
console.log(Object.getPrototypeOf(Object.prototype)); // null

Footnotes

[fn:defaultmethods]https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global\_Objects/Object