let date = new Date('2014-04-23 18:55:49:123');
// 有三种方式获取
let time1 = date.getTime();
let time2 = date.valueOf();
let time3 = Date.parse(date);
console.log(time1);//1398250549123
console.log(time2);//1398250549123
console.log(time3);//1398250549000