deep copy JS object

deepCopy.js

let o1 = { p1: 'v1', p2: { p3: 'v3' }, p4: ['a', 'b', 'c'], p5: 1, p6: false, p7: null, p8: undefined };
 
function deepCopy(o) {
  let o_copy = {}
  for (var p in o) {
    if (o.hasOwnProperty(p)) {
      if (typeof o[p] === 'object' && !(Array.isArray(o[p]) || o[p] == null)) {
        o_copy[p] = deepCopy(o[p]);
      } else {
        o_copy[p] = o[p]
      }
    }
  }
  return o_copy;
}
 
let o2 = deepCopy(o1);

// note the following works for all values other than 'undefined':

let o2 = JSON.parse(JSON.stringify(o1));