Simple handwritten debounce function

function debounce(cb, timeout = 300) {
    
  //  Closure a last trigger time 
  let lastEmitTime;
  return function () {
    
    //  Each call updates the last trigger time 
    lastEmitTime = new Date().valueOf();
    setTimeout(() => {
    
      //  Set up timeout After the time, compare whether the last call time has exceeded the setting timeout  Call when it exceeds callback
      const currentTime = new Date().valueOf();
      if (currentTime - lastEmitTime >= timeout) {
    
        cb(...arguments);
      }
    }, timeout);
  };
}