js中将yyyy-MM-dd格式的日期转换

1.转换为yyyy年MM月dd日

 var str = "2017-02-16";
    var reg =/(\d{4})\-(\d{2})\-(\d{2})/;
    var date = str.replace(reg,"$1年$2月$3日");
    alert(date);

2.转换为yyyy/MM/dd/

 var str = "2017-02-16";
    var reg =/(\d{4})\-(\d{2})\-(\d{2})/;
    var date = str.replace(reg,"$1/$2/$3");
    alert(date);

其他转换都类似 。主要是用正则表达式匹配