how to find keys in an object javascript mdn code example

Example 1: object.keys

const object1 = {
  a: 'somestring',
  b: 42,
  c: false
};

console.log(Object.keys(object1));
// expected output: Array ["a", "b", "c"]

Example 2: 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"]