One possible solution could be
/**
 * @param {string} string
 * @return {string}
 */
function capitalize(string) {
  return string.charAt(0).toUpperCase() + string.slice(1);
}

/**
 * @param {string} string
 * @return {string}
 */
function camelCase(string) {
  let parsedString = string.toLowerCase();

  return parsedString
    .replace(/(? {
      return capitalize(p0);
    })
    .replace(/[^a-zA-Z0-9]/g, '');
}

/**
 * @param {object|array} collection
 * @return {object}
 */
function camelCaseKeys(collection) {
  // checking if the input collection is an array
  const isCollectionArray = Array.isArray(collection);

  if (isCollectionArray) {
    // if empty array then return the original input
    if (!collection.length) {
      return collection;
    }

    // iterate over the array and
    // invoke the camelCaseKeys method on each item
    return collection.map((item) =&gt; camelCaseKeys(item));
  }

  // check if collection is object
  const isCollectionObject = typeof collection === 'object';

  // if not object or null then return original input
  if (!isCollectionObject || collection === null) {
    return collection;
  }

  // get each key and value
  // [['total_question', 1], ...]
  const keyValues = Object.entries(collection);

  // iterate over the key value pair and convert to camelCase
  const convertedCollection = keyValues.map(([key, value]) =&gt; {
    return [
      camelCase(key),
      typeof value === 'object' ? camelCaseKeys(value) : value,
    ];
  });

  // reconstruct the original collection and return
  return Object.fromEntries(convertedCollection);
}
Do you see value in our efforts?

Implement a function to convert all object keys to camel case | JavaScript Interview Question

@Yomesh Gupta
