从json数据树中获取对象，函数重用问题

{
  "name": "John",
  "age": 30,
  "address": {
    "street": "123 Main St",
    "city": "New York"
  }
}

var jsonData = '{"name": "John", "age": 30}';
var obj = JSON.parse(jsonData);
var name = obj.name;
console.log(name); // Output: John

var jsonData = '{"name": "John", "age": 30, "address": {"street": "123 Main St", "city": "New York"}}';
var obj = JSON.parse(jsonData);
var city = obj.address.city;
console.log(city); // Output: New York

var jsonData = '{"name": "John", "age": 30}';
var obj = JSON.parse(jsonData);
var propertyName = "name";
var value = obj[propertyName];
console.log(value); // Output: John

function getObjectFromJson(jsonData, path) {
  var obj = JSON.parse(jsonData);
  var properties = path.split('.');
  var result = obj;
  
  for (var i = 0; i < properties.length; i++) {
    result = result[properties[i]];
    if (result === undefined) {
      break;
    }
  }
  
  return result;
}

// 使用示例
var jsonData = '{"name": "John", "age": 30, "address": {"street": "123 Main St", "city": "New York"}}';
var path = 'address.city';
var city = getObjectFromJson(jsonData, path);
console.log(city); // Output: New York