Callback in a for loop with async operation

Question

What is the best way to call a callback function after completion of an async call for all elements of array, from within a for loop?

Currently I am checking for iterator to match length of array as follows, but I want to know if there is a better way.

exports.myFunction = function (arr, callback) {
    for (var i = 0; i < arr.length; i++) {
        (function (i) {
            var comp = arr[i];

            // do other calculations

            // call an async function
            asyncOperation(comp, function(response){
                // further changes in response here

                // if last array element, call callback()
                if (i == arr.length - 1) {
                    // call the callback...
                    callback();
                }
            });
        })(i);
    }
}

Can you please suggest the best approach for this kind of situation?