+new Date()特性
+new Date(),结果跟Date对象的getTime(),valueOf()是一样的,他们返回的都是时间戳
var date=new Date(); console.log(+date) console.log(date.getTime()) console.log(date.valueOf())
var date=new Date(); console.log(+date) console.log(date.getTime()) console.log(date.valueOf())