节流函数

  1. /**
  2. * @param {Function} fn 函数
  3. *    @param {Number} time 时间
  4. */
  5. function throttle(fn, time) {
  6.     let previous = 0
  7.   return function() {
  8.       const now = Date.now()
  9.     const that = this
  10.     const args = arguments
  11.     if (now - previous > time) {
  12.         fn.apply(that, args)
  13.       previous = now
  14.     }
  15.   }
  16. }

防抖函数

  1. /**
  2. * @param {Function} fn 函数
  3. *    @param {Number} time 延迟执行毫秒数
  4. * @param {Boolean} immediate true - 立即执行 false - 延迟执行
  5. */
  6. function debounce(fn, time = 1000, immediate = true) {
  7.     let timer
  8.   return function() {
  9.       const that = this
  10.     const args = arguments
  11.     if (timer) {
  12.         return clearTimeout(timer)
  13.     }
  14.     if (immediate) {
  15.         const callNow = !timer
  16.       timer = setTimeout(() => {
  17.           timer = null
  18.       }, time)
  19.       if (callNow) {
  20.           fn.apply(that, args)
  21.       }
  22.     } else {
  23.         timer = setTimeout(() => {
  24.           fn.apply(that, args)
  25.       }, time)
  26.     }
  27.   }
  28. }