Javascript – Age Caluculator, Caluculating Age, How to calculate age in javascript.
Below codes divided into two parts, one part in head tag and another tag in body.Â
<html>
<head>
<!– AGE CALCULATOR –>
<script language=”JavaScript” type=”text/javascript”>
<!–
function getAge() {
 month = (document.form1.month.value – 1);
 date = document.form1.date.value;
 year = document.form1.year.value;
 if (month != parseInt(month)) { alert(’Type Month of birth in digits only!’); return false; }
 if (date != parseInt(date)) { alert(’Type Date of birth in digits only!’); return false; }
 if (year != parseInt(year)) { alert(’Type Year of birth in digits only!’); return false; }
 if (year.length < 4) { alert(’Type Year of birth in full!’); return false; }
 today = new Date();
 dateStr = today.getDate();
 monthStr = today.getMonth();
 yearStr = today.getFullYear();
 theYear = yearStr – year;
 theMonth = monthStr – month;
 theDate = dateStr – date;
 var days = “”;
 if (monthStr == 0 || monthStr == 2 || monthStr == 4 || monthStr == 6 || monthStr == 7 || monthStr == 9 || monthStr == 11) days = 31;
 if (monthStr == 3 || monthStr == 5 || monthStr == 8 || monthStr == 10) days = 30;
 if (monthStr == 1) days = 28;
 document.form1.inYears.value = theYear;
 if (month < monthStr && date > dateStr) { document.form1.inYears.value = parseInt(document.form1.inYears.value) + 1;
                                          document.form1.inMonths.value = theMonth – 1; }
 if (month < monthStr && date <= dateStr) { document.form1.inMonths.value = theMonth; }
 else if (month == monthStr && (date < dateStr || date == dateStr)) { document.form1.inMonths.value = 0; }
 else if (month == monthStr && date > dateStr) { document.form1.inMonths.value = 11; }
 else if (month > monthStr && date <= dateStr) { document.form1.inYears.value = document.form1.inYears.value – 1;
                                                document.form1.inMonths.value = ((12 – -(theMonth)) + 1); }
 else if (month > monthStr && date > dateStr) { document.form1.inMonths.value = ((12 – -(theMonth))); }
 if (date < dateStr) { document.form1.inDays.value = theDate; }
 else if (date == dateStr) { document.form1.inDays.value = 0; }
 else { document.form1.inYears.value = document.form1.inYears.value – 1; document.form1.inDays.value = days – (-(theDate)); }
 }
// –>
</script>
</head>
<body>
<form name=”form1″>
<table align=”center” width=”380″ border=”0″ cellpadding=”0″ cellspacing=”0″>
 <tr>
 <td align=”center”>
  MM: <input type=”text” maxLength=”2″ size=”2″ name=”month” value=”01″ />Â
  DD: <input type=”text” maxLength=”2″ size=”2″ name=”date” value=”30″ />Â
  YYYY: <input type=”text” maxLength=”4″ size=”4″ name=”year” value=”1990″ />
  <input type=”button” value=”Get Age” onClick=”getAge()” /><br /><br />
 </td>
 </tr>
 <tr>
 <td align=”center”>
  <table border=”0″ cellpadding=”0″ cellspacing=”0″ width=”120″>
   <tr><td align=”right”><input type=”text” size=”2″ name=”inYears” value=”" /></td><td align=”left”>Years</td></tr>
   <tr><td align=”right”><input type=”text” size=”2″ name=”inMonths” value=”" /></td><td align=”left”>Months</td></tr>
   <tr><td align=”right”><input type=”text” size=”2″ name=”inDays” value=”" /></td><td align=”left”>Days</td></tr>
  </table>
 </td>
 </tr>
</table>
</form>
</body>
</html>
Click here to download source code Age calculator
javascript should be little more conservative
Thanks for your comments, I will try to find a time to do it for you.
Rana
Thanks for the downloads, …