What is the type of “keys” in JavaScript?

Question

I bumbed into one of those moments when I just lose the focus and start wondering on a silly question:

var a = {
  b: \"value\"
}

What is t

Answer 1

var a = {$ : 'hello', 2123 : 'number'};
for(var key in a) {
  console.log(typeof key)
}

Keys in javascript objects can be strings and symbols. symbol is a primitive data type in javascript.