JS封装节流函数

function throttle(func, delay) {
  let timer = null;
  let lastRunTime = 0;
  return function() {
    let context = this;
    let args = arguments;
    let currentTime = Date.now();
    clearTimeout(timer);
    if (currentTime - lastRunTime >= delay) {
      func.apply(context, args);
      lastRunTime = currentTime;
    } else {
      timer = setTimeout(function() {
        func.apply(context, args);
        lastRunTime = Date.now();
      }, delay);
    }
  };
}
// 例子：每隔500ms打印一次当前时间
function printTime() {
  console.log(new Date().toLocaleTimeString());
}
const throttledPrintTime = throttle(printTime, 500);
setInterval(throttledPrintTime, 100);