Debounce Implementation

debounce.js

function debounce(func, wait) {
  // we need to save these in the closure
  var timeout, args, context, timestamp;
  return function () {
    // save details of latest call
    context = this;
    args = [].slice.call(arguments, 0);
    timestamp = new Date();
    // this is where the magic happens
    var later = function () {
      // how long ago was the last call
      var last = (new Date()) - timestamp;
      // if the latest call was less that the wait period ago
      // then we reset the timeout to wait for the difference
      if (last < wait) {
        timeout = setTimeout(later, wait - last);
        // or if not we can null out the timer and run the latest
      } else {
        timeout = null;
        func.apply(context, args);
      }
    };
    // we only need to set the timer now if one isn't already running
    if (!timeout) {
      timeout = setTimeout(later, wait);
    }
  };
}