当浏览器窗口中显示div或css时运行Jquery - 新手和困惑

Question

我是这方面的新手，这个问题可能已经得到了解答。当div或类可见且函数只运行一次时，如何让我的Jquery函数开始。

$.fn.isInViewport = function() {
  var elementTop = $(this).offset().top;
  var elementBottom = elementTop + $(this).outerHeight();

  var viewportTop = $(window).scrollTop();
  var viewportBottom = viewportTop + $(window).height();

  return elementBottom > viewportTop && elementTop < viewportBottom;
};

$(window).on('resize scroll', function() {
        ('.count').each(function() {
          $(this).prop('Counter', 0).animate({
            Counter: $(this).text()
          }, {
            duration: 4000,
            easing: 'swing',
            step: function(now) {
              $(this).text(Math.ceil(now));
           }}
      );
      });

    }); 

<div id="fico_scroll">
  <div id="fico-11"><span class="count">495</span></div>
  <div id="fico-2"><span class="count">722</span></div>
  <div id="fico-3"><span class="count">608</span></div>
  <div id="fico-4"><span class="count">805</span></div>
  <div id="fico-5"><span class="count">533</span></div>
  <div id="fico-6"><span class="count">685</span></div>
  <div style="clear:both"></div>
</div>