Customizing counter in a html page

Question

Below is an example of establishing a counter in html (sourced from internet).

JS

$(document).ready(function() {
      var positionFromTop = 100; 
        $(window).scroll(function() {
          var $y = $(window).scrollTop();
          if ($y >= positionFromTop) {
             var i;
             for (i = 0; i <= 5400; i += 100) { 
                setTimeout(Counter_Fn(i), 3000);
            }
        }
    });
    });

    function Counter_Fn(x) {
        document.getElementById("Counter_1").innerHTML = x;
    }

body {
  background-color: #F46A6A;
  color: #fff;
  max-width: 800px;
  margin: 1000px auto 0;
  text-align: center;
  display: table;
}

.counter {
  display: table-cell;
  margin: 1.5%;
  font-size: 50px;
  background-color: #FF6F6F;
  width: 200px;
  border-radius: 50%;
  height: 200px;
  vertical-align: middle;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>


<div id = "Counter_1" class="counter">0</div>

While this is serving basic purpose of mine, but I want to add few more details as below

1. I want counter should start when I scroll down to a specific point (once page is loaded). In current example, counter just starts when page load, not waiting for me till I reach it's position below
2. Increment should be 100 not 1
3. I also want to have comma seperator after 1,000

Any pointer to achieve above functionalities will be highly appreciated

Answer 1

1) To run some code when user scrolls down to a certain point in page, you should put your code inside a function, and then, in the $(document).ready(), you should use:

$(document).ready(function() {
  var positionFromTop = 1234; // for example
  $(window).scroll(function() {
    var $y = $(window).scrollTop();
    if ($y >= position) {
      callyourFunctionToCount();
    }
  });
}

2) To use a step different from 1 you can't use animate(). You should use some sort of a timed counter, like it is well described here, for example. https://stackoverflow.com/a/2540673/709439.

3) The same as for point 2: using a counter it becomes easy to set your increment value and the output format.