Javascript:计算从出生年份到今天的天、小时、分钟、秒

Question

在我的程序中，通过提示值，我正在计算出生年份、下一年、天、小时、分钟和秒。现在我想计算这个人从出生之日起已经活了多长时间。为此，我做了下面的计算，但我对存活天数、小时、分钟、秒数的计算显示不正确。有人可以帮忙吗？

var monthNames = ["January", "February", "March", "April", "May", "June",
  "July", "August", "September", "October", "November", "December"
];

var days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];

var today = new Date();

var myMonth = prompt("What month were you born in?");
var myDay = prompt("What day were you born on?");
var myYear = prompt("What year were you born in?");

var birthday = new Date(myYear, myMonth, myDay);

var dateLoc = document.getElementById("dateField").innerHTML = "Today is " + today;

var birthField = document.getElementById("birthField")
  .innerHTML = "I was born on " + monthNames[myMonth - 1] + ' ' + myDay + ', ' + myYear + '.' +
  '(' + myMonth + '/' + myDay + '/' + myYear + ')';

var milliseconds, seconds, minutes, hours, days;

var years = today.getFullYear() - birthday.getFullYear();

myMonth--;
var nextBirthday = (new Date(today.getFullYear(), myMonth, myDay)) < today ? (new Date(today.getFullYear() + 1, myMonth, myDay)) : (new Date(today.getFullYear(), myMonth, myDay))

console.log(nextBirthday);

milliseconds = diff % 1000;
diff = (diff - (milliseconds)) / 1000;

seconds = diff % 60

diff = (diff - seconds) / 60;

minutes = diff % 60
diff = (diff - minutes) / 60;

hours = diff % 24
days = (diff - hours) / 24;

var nextBirth = document.getElementById("nextBirth").innerHTML = "I am " + years + "  Years old, and will turn " + (years + 1) + " in:" + "<br>" + days + " days, " + hours + " hours, " + minutes + " minutes, " + seconds + " seconds";

milliseconds = diffAlive % 1000;
diffAlive = (diffAlive - (milliseconds)) / 1000;

seconds = diffAlive % 60

diffAlive = (diffAlive - seconds) / 60;

minutes = diffAlive % 60
diffAlive = (diffAlive - minutes) / 60;

hours = diffAlive % 24
days = (diffAlive - hours) / 24;


var aliveFor = document.getElementById("aliveFor").innerHTML = "I have been alive for..." + "<br>" + days + " days, " + hours + " hours, " + minutes + " minutes, " + seconds + " seconds";

p {
  text-align: center;
  font-family: monospace;
  font-size: 20px;
}

body {
  background-image: url(birth.jpg");
  background-repeat: no-repeat;
  background-size: 1300px 600px;
}

<p id="dateField"> </p>
<p id="birthField"> </p>
<p id="nextBirth"> </p>
<p id="aliveFor"> </p>

输出:

Answer 1

您传递给 Date 的月份错误计算生日时的构造函数。它是从 0 开始的。

将 myMonth-- 行移至设置生日变量之前。

例如

myMonth--;
var birthday = new Date(myYear, myMonth, myDay);