javascript - 使用提示中的答案进行计算

Question

JavaScript 完全新手。

我想通过提示/警报询问用户的出生日期来计算一个人还活着多少天，然后显然从今天的日期中减去他们的出生日期。

我已经开始了......

var month=prompt("Please enter month of birth"," "); 
var day=prompt("Please enter day of birth"," "); 
var year=prompt("Please enter your year of birth"," ");

var curdate = this is the bit i need help with 
var birth = this is the bit i need help with

var milliDay = 1000 * 60 * 60 * 24; // a day in milliseconds;

var ageInDays = (curdate - birth) / milliDay;

document.write("You have been alive for: " + ageInDays);

任何建议或帮助将不胜感激。

Answer 1

您需要使用Date object (MDN) 。它们可以根据一个月、一天和一年创建，并进行添加/减去。

通常:

var curDate = new Date();
var birth = new Date(year, month, day);

var ageInDays = (curdate.getTime() - birth.getTime()) / milliDay;

请注意月份从 0 开始，例如一月是 0。