debounce还是throttle(去抖和节流)

debounce 去抖

我的理解很简单，比方说window.onscroll会疯狂触发handler，此时给它一个debounce(handler, delayTime).

就是不管你延时时间内触发了多少hanlder，我最后只执行一次。（理解把之前多次触发合并成一次，节省浏览器工作）

function debounce(fn, delay) {

  var ctx

  var args

  var timer = null

  var later = function () {

    fn.apply(ctx, args)

    timer = null

  }

  return function () {

    ctx = this

    args = arguments

    if (timer) {

      clearTimeout(timer)

      timer = null

    }

    timer = setTimeout(later, delay)

  }

}

throttle 节流

不管你怎么触发#24，反正我就是固定时间内必定触发一次

function throttle(fn, delay) {

  var ctx

  var args

  var previous = Date.now()

  var later = function () {

    fn.apply(ctx, args)

  }

  return function () {

    ctx = this

    args = arguments

    var now = Date.now()

    var diff = now - previous - delay

    if (diff >= 0) {

      previous = now

      setTimeout(later, delay)

    }

  }

}

以上参考地址：https://segmentfault.com/a/1190000005926579

我在想 throttle可以这样改吗。。。

function throttle(fn, delay) {

  var ctx

  var args

  var timer = null

  var later = function () {

    fn.apply(ctx, args)

    timer = null

  }

  return function () {

    ctx = this

    args = arguments

    if (timer) return

    timer = setTimeout(later, delay)

  }

}

哈哈这段我没测试鸭（懒癌）。错了请告诉我我删掉