如何展平不同对象的嵌套数组，但只从现有的属性名称中获取值？

function flattenObject(obj, prefix = '') {
  let result = {};

  for (let key in obj) {
    if (Array.isArray(obj[key])) {
      obj[key].forEach((item, index) => {
        const newPrefix = prefix + key + '[' + index + '].';
        Object.assign(result, flattenObject(item, newPrefix));
      });
    } else if (typeof obj[key] === 'object' && obj[key] !== null) {
      const newPrefix = prefix + key + '.';
      Object.assign(result, flattenObject(obj[key], newPrefix));
    } else {
      result[prefix + key] = obj[key];
    }
  }

  return result;
}

const nestedObj = {
  name: 'John',
  age: 30,
  address: {
    street: '123 Main St',
    city: 'New York',
    state: 'NY',
    zip: '10001'
  },
  hobbies: ['reading', 'painting', 'coding']
};

const flattenedObj = flattenObject(nestedObj);
console.log(flattenedObj);

{
  'name': 'John',
  'age': 30,
  'address.street': '123 Main St',
  'address.city': 'New York',
  'address.state': 'NY',
  'address.zip': '10001',
  'hobbies[0]': 'reading',
  'hobbies[1]': 'painting',
  'hobbies[2]': 'coding'
}