日期格式化 在网页上显示当前日期

var time = new Date();
    var year = time.getFullYear();//年
    var yue = time.getMonth() + 1;//月
    yue = yue<10?'0'+yue:yue;
    var ri = time.getDate();//日
    ri = ri<10?'0'+ri:ri;
    var week1 = time.getDay();//星期
    var week = '';
    switch (week1) {
        case 0:
            week = '天'
            break;
        case 1:
            week = '一'
            break;
        case 2:
            week = '二'
            break;
        case 3:
            week = '三'
            break;
        case 4:
            week = '四'
            break;
        case 5:
            week = '五'
            break;
        case 6:
            week = '六'
            break;

    }
    var shi = time.getHours();//小时
    var fen = time.getMinutes();//分钟
    fen = fen<10?'0'+fen:fen;
    var miao = time.getSeconds();//秒
    miao = miao<10?'0'+miao:miao;
    document.write(`
            ${year}-${yue}-${ri}&nbsp; ${shi}:${fen}:${miao} 星期${week} 
    `)