GoCareerGo Tutorials

JavaScript Tutorial

Variables to closures, promises, the DOM and OOP — a complete JS reference.

ES6 Classes

Syntactic sugar over JavaScript's existing prototype-based inheritance, giving OOP code a familiar class syntax.

class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    return `${this.name} makes a sound.`;
  }
}

const dog = new Animal('Rex');
dog.speak(); // 'Rex makes a sound.'

Classes are NOT hoisted the same way functions are (they stay in the TDZ)
Class bodies always run in strict mode
Methods defined on the class live on the prototype, not each instance