let d = new Date(val)//生日val:1999-01-01
let t = d.getTime(d) // 转换为时间戳
var t1 = Date.parse(new Date());//获取当前时间戳
let t2 = t1 - t;//计算时间戳之差
t2 = t2 / 1000 / (60 * 60 * 24 * 30 * 12)//将差值转换为年
t2 = Math.floor(t2)//向下取整
this.entityForm.age = t2;
console.log(t2);
来源:https://www.cnblogs.com/qiangyanhuanxiao/p/14651782.html