1.转换为yyyy年MM月dd日
var str = "2021-09-13";
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 = "2021-09-13";
var reg =/(\d{4})\-(\d{2})\-(\d{2})/;
var date = str.replace(reg,"$1/$2/$3");
alert(date);
3.转换为yyyyMMdd
var str = "2021-09-13";
var reg =/(\d{4})\-(\d{2})\-(\d{2})/;
var date = str.replace(reg,"$1$2$3");
alert(date);