js obj with function stringify

obj2str.js

function obj2str(obj) {
  var fString = function(objj) {
    if (!objj) return objj;
    var newObj = Array.isArray(objj) ? [] : {}
    Object.keys(objj).map(function(k) {
      if (typeof(objj[k]) == "function") newObj[k] = objj[k].toString();
      else if (typeof(objj[k]) == "object") newObj[k] = fString(objj[k]);
      else newObj[k] = objj[k];
    })
    return newObj;
  };
  var newObj = fString(obj);
  return JSON.stringify(newObj);
}
function str2obj(str) {
  var fsObject = function(objfs) {
    if (!objfs) return objfs;
    Object.keys(objfs).map(function(k) {
      if (/^function/.test(objfs[k])) eval("objfs[k] = " + objfs[k]);
      else if (typeof(objfs[k]) == "object") fsObject(objfs[k]);
    })
  };
  var obj = JSON.parse(str);
  fsObject(obj);
  return obj;
}