convert a JSON keys to camel case

convertToCamelCase.js

// convert a key string to camelcase
function toCamelCase(str) {
  // when str is not defined reuturn
  if (!str) {
    return str;
  }

  return str.charAt(0).toLowerCase() + str.substring(1);
}

// convert all keys in a json to camelcase
// NOTE: JSON parsing is not done here
// so before calling this function JSON should be parsed
function convertToCamelCase(json) {
  // check if it is an array
  if (Array.isArray(json)) {
    return json.map(el => convertToCamelCase(el));
  }

  // check if it is an object
  if (typeof json === "object") {
    let newJson = { ...json };
    Object.keys(newJson).forEach(key => {
      // convert the key to camel case
      const newKey = toCamelCase(key);
      // copy the converted value of this key to a new variable
      const value = convertToCamelCase(newJson[key]);
      // remove the key from the json
      delete newJson[key];
      // replace the value under new converted key
      newJson[newKey] = value;
    });
    return newJson;
  }

  // if it is not object or array
  // then return as it is
  return json;
}