md(){
    let ymd =2021-02-21
    this.getWeek(ymd ) //调用
　　console.log(this.getWeek(ymd )) //打印

}

 getWeek(ymd) { //把日期转为周几文字
    // console.log(dateString)
    var dateArray = ymd.split("-");
    // console.log(dateArray)
    let date = new Date(dateArray[0], parseInt(dateArray[1] - 1), dateArray[2]);
    return "周"+"日一二三四五六".charAt(date.getDay());
　　//或者字数
},

 getWeek(ymd) { //把日期转为周几数字
    // console.log(dateString)
    var dateArray = ymd.split("-");
    // console.log(dateArray)
    let date = new Date(dateArray[0], parseInt(dateArray[1] - 1), dateArray[2]);
    return "123456".charAt(date.getDay());
　　//或者字数
},