javascript时间日期格式化实例代码

<script>
function dateFormat(date,format) 
{
  if(format===undefined)
  {
    format=date;
    date=new Date();
  }
  var map={
    "M": date.getMonth() + 1, //月份
    "d": date.getDate(), //日
    "h": date.getHours(), //小时
    "m": date.getMinutes(), //分
    "s": date.getSeconds(), //秒
    "q": Math.floor((date.getMonth() + 3) / 3), //季度
    "S": date.getMilliseconds() //毫秒
  };
    
  format = format.replace(/([yMdhmsqS])+/g,function(all, t){
    var v = map[t];
    if(v !== undefined)
    {
      if(all.length > 1)
      {
        v = '0' + v;
        v = v.substr(v.length-2);
      }
      return v;
    }
    else if(t === 'y')
    {
      return (date.getFullYear() + '').substr(4 - all.length);
    }
    return all;
  });
  return format;
}
console.log(dateFormat('yyyy-MM-dd hh:mm:ss'));
console.log(dateFormat(new Date(), 'yyyy-MM-dd hh:mm:ss'));
console.log(dateFormat('yyyy-MM-dd'));
</script>