javascript:将数字转换为时间

function convertToTime(num) {
  var date = new Date(num);
  var hours = date.getHours();
  var minutes = date.getMinutes();
  var seconds = date.getSeconds();
  
  // 格式化处理
  hours = (hours < 10) ? "0" + hours : hours;
  minutes = (minutes < 10) ? "0" + minutes : minutes;
  seconds = (seconds < 10) ? "0" + seconds : seconds;
  
  return hours + ":" + minutes + ":" + seconds;
}

var num = 1622757545707; // 要转换的数字
var time = convertToTime(num);
console.log(time); // 输出：14:52:25