get property of item js code example

Example 1: javascript list object properties

var person={"first_name":"Bill","last_name":"Jenner"}
//get the person object properties with:
var keys = Object.keys(person); //keys = ["first_name","last_name"]

Example 2: javascript list class properties

function getClassProperties(instanceOfClass) {
  const proto = Object.getPrototypeOf(instanceOfClass);
  const names = Object.getOwnPropertyNames(proto);
  return names.filter(name => name != 'constructor');
}