If this topic is limited to the DEMO you provided and interpreted with a general method:

Array.prototype.toCamelCase = function(keys) {
    keys  = keys || { CARID: 'carId', CARNO: 'carNo' };
    return this.map(item => {
        let newItem = {};
        for (let ii in item) {
            newItem[keys[ii] || ii] = item[ii];
        }
        return newItem;
    });
}

console.log(JSON.stringify(data.toCamelCase()));
// [{"carId":"111","carNo":"1111"},{"carId":"222","carNo":"2222"},{"carId":"333","carNo":"3333"}]
console.log(JSON.stringify(data.toCamelCase({ CARID: 'carID', CARNO: 'carNO' })));
// [{"carID":"111","carNO":"1111"},{"carID":"222","carNO":"2222"},{"carID":"333","carNO":"3333"}]

It will be difficult to exceed it any further.

It’s actually very troublesome. You first need to have a dictionary with all the words in it, and then separate the key names into individual words according to the dictionary and then convert them into camel case format and then combine them.

You can imagine how troublesome this is.