// https://babeljs.io/docs/en/babel-plugin-proposal-class-properties class Bork { //Property initializer syntax instanceProperty = "bork"; boundFunction = () => { return this.instanceProperty; }; //Static class properties static staticProperty = "babelIsCool"; static staticFunction = function () { return Bork.staticProperty; }; } let myBork = new Bork(); //Property initializers are not on the prototype. console.log(myBork.__proto__.boundFunction); // > undefined //Bound functions are bound to the class instance. console.log(myBork.boundFunction.call(undefined)); // > "bork" //Static function exists on the class. console.log(Bork.staticFunction()); // > "babelIsCool"