Javascript Array delayed interval iterator

delayedItervalArrayIterator.js

//Iterates over each item in an array at a delayed interval (1500ms)
Array.prototype.iterate = function (callback, onFinished) {
    var self = this;
    
    (function get(index){
        setTimeout(function(){
            if(index < self.length) {
                callback(self[index], index);
                get(index + 1);
            } else {
               if(typeof onFinished !== 'undefined') onFinished() ;
            }
        }, 1500);
    })(0);
};

//Example usage
var items = ["a", "b", "c"]

items.iterate(function(item, index) {
  console.log(item)
});