const $ = s => document.querySelector(s)

​

let count = 0

save = throttle(save, 1000 * 3)

$('#box').oninput = function() {

  save()

}

​

function save() {

  $('#count').innerText = ++count

}

​

function throttle(fn, gapTime) {

  let lastTime = null

  let nowTime = null

  return function() {

    nowTime = Date.now()

    if (!lastTime || nowTime - lastTime > gapTime) {

      fn()

      lastTime = nowTime

    }

  }

}