js获取当前日期

基本思路都是从Date对象中获取当前日期
区别是前者使用toLocaleDateString()配上正则；
后者是getTime()获取时间戳，再实例化Date对象，从中获取时间

方法1：  

var a= (new Date()).toLocaleDateString();//获取当前日期
a = a.replace(///g,'-');//替换2017/05/03 为2017-05-03
//console.log(a);
//console.log(new Date());



方法2：  

//var oldTime = Math.round(new Date().getTime())-86400000;
var oldTime = Math.round(new Date().getTime());
var d = new Date(oldTime);
function add0(m) {
    return m < 10 ? '0' + m : m
}
function formatDate(now) {
    var year = now.getFullYear();
    var month = now.getMonth() + 1;
    var date = now.getDate();
    var hour = now.getHours();
    var minute = now.getMinutes();
    var second = now.getSeconds();
    //return year+"-"+add0(month)+"-"+add0(date)+" "+add0(hour)+":"+add0(minute)+":"+add0(second);
    return year + "-" + add0(month) + "-" + add0(date);
}
var preTime = formatDate(new Date());
//var preTime = formatDate(d);
//console.log(preTime);