js獲取當前時間，返回日期yyyy-MM-dd

this.now_year = new Date().getFullYear();
this.now_month = new Date().getMonth() + 1;
this.now_day = new Date().getDate();

//now_time 當前日期
let now_time ="";
now_time+=this.now_year;
            
if(this.now_month<10){
      now_time+= '-0'+this.now_month;
      if(this.now_day<10){
            now_time+= '-0'+this.now_day;
      }else{
            now_time+= '-'+this.now_day;
      }
}else{
      now_time+='-'+ this.now_month;
      if(this.now_day<10){
             now_time+= '-0'+this.now_day;
      }else{
             now_time+= '-'+this.now_day;
      }
}