Advice for directing further learning

If you have an object var o = {n:3,s:"str"}and you try array-access the properties, no matter what numeric value you put into the square bracket, it does not give you properties back... because the number is just another 'name'... but you can use it to add more attributes, for example:

var o = {n:3,s:"str"};
console.log("o[1]:", o[1]); // ---> undefined
o[1]="x1"; // ---> adds new property w/ (numeric)  name ```1``` to object ```o```
          //       and set the properties value to string "x1"
console.log("o[1]:",o[1]); // ---> access/show property w/ name ```1```: ---> "x1"




o[1]: undefined
o[1]: x1