simple throttle and debounce

debounce.js

  /**
   * @param {number} delay
   * @param {Function} callback
   * @returns {Function}
   */
  function debounce(delay, callback) {
    var timer = 0;
    return function () {
      var self = this;
      var args = arguments;
      if (timer) {
        clearTimeout(timer);
        timer = 0;
      }
      timer = setTimeout(function () {
        callback.apply(self, args);
      }, delay);
    };
  }

throttle.js

/**
 * @param {number} delay
 * @param {Function} callback
 * @returns {Function}
 */
function throttle(delay, callback) {
  var timer = 0;
  var lastExec = 0;
  return function () {
    var self = this;
    var args = arguments;
    var elapsed = Date.now() - lastExec;

    function exec() {
      lastExec = Date.now();
      callback.apply(self, args);
    }

    if (timer) {
      clearTimeout(timer);
      timer = 0;
    }
    if (elapsed > delay) {
      exec();
    } else {
      timer = setTimeout(exec, delay - elapsed);
    }
  };
}