手写下划线转驼峰命名要考虑对象的深度递归情况

看别人的面经发现一道题，一时手痒就写了下，不知道对错。

题源：https://www.nowcoder.com/discuss/470638184494276608

const underscoreToCamelCase = (data) => {
  if (Array.isArray(data)) {
    return data.map(underscoreToCamelCase);
  } else if (typeof data === "object" && data != null) {
    const res = {};
    for (const key in data) {
      let newKey = "";
      if (key.indexOf("_") != -1) {
        let upper = false;
        for (let i = 0; i < key.length; i++) {
          if (key.charAt(i) === "_") {
            upper = true;
            continue;
          }
          newKey += upper ? key.charAt(i).toUpperCase() : key.charAt(i);
          upper = false;
        }
      }
      res[newKey ? newKey : key] = underscoreToCamelCase(data[key]);
    }
    return res;
  } else {
    return data;
  }
};
// 测试
const data = {
  first_name: "John",
  last_name: "Doe",
  age: 30,
  address: {
    city_name: "New York",
    country_code: "US",
  },
  hobbies: ["reading_books", "playing_games"],
};
console.table(underscoreToCamelCase(data));