3CBwithProgressBar created by yodacom - https://repl.it/HpJh/1
// Writing a simple progress bar function in the callback style. Function takes three callbacks, onStart, onProgress, and onEnd as arguments. When you call the function it should call the onStart callback, then loop from 1 to 100, using console.log to print each value. Every 10 items it counts it should call the onProgress callback, providing how far along it is as an argument. Finally it should call the onEnd callback.
function callbackProgBar(onStart, onProgress, onEnd){
var startNum = 1;
var nextNum = [];
onStart(function(){
var lastNum = nextNum ++;
push(nextNum);
if (nextNum % 10) {
console.log(nextNum)}
else if (nextNum = endNum ) {
onEnd();
};
};