防抖节流.md

防抖

function debounce(fn, delay) {
  let timer = null;
  return function () {
    if (timer) {
      clearTimeout(timer);
    }
    timer = setTimeout(() => {
      fn.apply(this, arguments);
    }, delay);
  };
}

节流

function throttle(fn, delay) {
  let canRun = true;
  return function () {
    if (!canRun) return;
    canRun = false;
    setTimeout(() => {
      fn.apply(this, arguments);
      canRun = true;
    }, delay);
  };
}

示例

function handleScroll() {
  console.log("scrolling...");
}
const debouncedHandleScroll = debounce(handleScroll, 1000);
window.addEventListener("scroll", debouncedHandleScroll);