在Javascript中显示来自DoB输入的年龄

Question

我正在尝试在html/javascript中创建一个表单，用户可以在其中输入他们的出生日期，然后显示一条消息，使用来自他们的出生日期的数据来说明“你是'x‘岁”。然而，我完全不确定如何让它工作？

下面是我目前掌握的代码：

HTML：

<input type="date" id="myBirthday" value="dd-mm-yyyy">
<button onclick="submitBirthday()">Submit</button>

JS：

function submitBirthday() {
    var birthday = document.getElementById("myBirthday").value;
    document.getElementById("displayBirthday").innerHTML = ("You are " + birthday + " years old.");
}

我意识到这会显示“你目前'dd-mm-yyyy‘岁，但这是我所能做的一切。

任何帮助都将不胜感激！谢谢

Answer 1

你可以用现在的日期减去出生日期来算出年龄。

请看这个。

How to subtract date/time in javascript?

Answer 2

根据This页面，以下是从指定日期检索年龄的固定代码：

​

function submitBirthday() {
    var minutes = 1000 * 60;
    var hours = minutes * 60;
    var days = hours * 24;
    var years = days * 365;

    var birthday = Date.parse(document.getElementById("myBirthday").value);
    var dateNow = new Date();
    var YearsOld = Math.round((dateNow-birthday)/ years);

    document.getElementById("displayBirthday").innerHTML = ("You are " + YearsOld + " years old.");
}

<input type="date" id="myBirthday" value="dd-mm-yyyy">
<button onclick="submitBirthday();">Submit</button>
<hr>
<div id="displayBirthday"></div>

​

Answer 3

下面是你可以用来获取出生日期的代码

var input = '5/1/1991';// Find the user's input
    var dob = input.split('/'); // split the date by separator
    //console.log(dob);
    var bd = dob[0];// find birth date, month and year
    var bm = dob[1];
    var by = dob[2];

    var curDate = new Date();// find current date
    var cd = curDate.getDate();
    var cm = parseInt(curDate.getMonth(), 10) + 1;
    var cy = curDate.getFullYear();
    //console.log(cd, cm, cy);

    if (cd < bd) {
        var dayToMinus;
        switch(cm) {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                dayToMinus = 31;
                break;
            case 4:
            case 6:
            case 9:
            case 11:
                dayToMinus = 30;
                break;
            case 2:
                if (cy % 4) {
                    dayToMinus = 28;
                } else {
                    dayToMinus = 29;
                }
        }
        cd = cd + dayToMinus;
        cm = cm - 1;
    }

    if (cm < bm) {
        cm = cm + 12;
        cy = cy - 1;
    }
    console.log("You are "+ (cy - by) +" years "+ (cm - bm) + " months "+ (cd - bd) + " days old");//This will console ur age