JS实现获取毫秒值及转换成年月日时分秒的方法

var date=new Date();

var date1=new Date("2017/08-26 15:15:15");

var date2=new Date(2017,9,18,23,15,23);

var date = Date.now();
var date = +new Date();
var date = new Date().getTime();
var date = new Date().valueOf();

var date=Date.parse("2017-05-24 18:23:14");

var date =new Date(Date.now());

console.log(getTime(1523604904000,1));
function getTime(second,getDateType) {
  var date =new Date(second);
  if(getDateType==0){
    return date.getFullYear();
  }else if(getDateType==1){
    if((date.getMonth()+1)<=9){
      return "0"+(date.getMonth()+1);
    }else {
      return date.getMonth()+1;
    }
  }else if(getDateType==2){
    if(date.getDate()<=9){
      return "0"+date.getDate();
    }else {
      return date.getDate();
    }
  }else if(getDateType==3){
    if(date.getHours()<=9){
      return "0"+date.getHours();
    }else {
      return date.getHours();
    }
  }else if(getDateType==4){
    if(date.getMinutes()<=9){
      return "0"+date.getMinutes();
    }else {
      return date.getMinutes();
    }
  }else if(getDateType==5){
    return date.getSeconds ();
  }else {
    alert("输入时间格式有误!");
    return;
  }
}