Semi-private members in JavaScript using Symbols

semi-private-members.js

function Constructor() {
 const privateMember = Symbol('privateMember'),
       publicMember = 'publicMember';
  
  this[privateMember] = 'foo';
  this[publicMember] = 'bar';
}

let c = new Constructor();

console.log(Object.keys(c));                // ['publicMember']
console.log(c['publicMember']);             // 'bar'
console.log(c['privateMember']);            // null
console.log(c[Symbol('privateMember')]);    // null