JavaScript: Object.getOwnPropertySymbols

New in JS2015.

Object.getOwnPropertySymbols(obj)

Return a Array of all own Symbol key properties . (including non-enumerable ones).

const ss = Symbol("ss");
const jj = {};
jj[ss] = 3;

console.log(jj[ss] === 3);

/* [ get a array of all symbol key properties ] */
console.log(Object.getOwnPropertySymbols(jj));
/* [ Symbol(ss) ] */

/* [ get a array of all symbol key properties ] */
console.log(Object.getOwnPropertySymbols(Array.prototype));
/* [
prints
[ Symbol(Symbol.unscopables), Symbol(Symbol.iterator) ]
] */