Detect the end of an async function inside a for loop in JavaScript

Question

I want to detect the end of an async function inside the for loop in JavaScript.

My code is:

  for (var i = 0; i < dataPoints.length; i++) {
  (function(i) {
    setTimeout(function() {


     if(end of everything)
     {
      //call xyz()
     }

    }, 5000 * i);
  })(i); 
}

Please help me in achieving my target. Thanks

Answer 1

You can just check if i is the last index of the array:

 dataPoints = [1, 2, 3]; 
 for (var i = 0; i < dataPoints.length; i++) {
  (function(i) {
    setTimeout(function() {
      console.log(i);

     if(i === dataPoints.length - 1) // if i is the last iteration
     {
      console.log('the end');
      //call xyz()
     }

    }, 1000 * i); // changed 5s to 1s for demo
  })(i); 
}