javascript calculate age

JavaScript
function getAge(dateString) 
{
    var today = new Date();
    var birthDate = new Date(dateString);
    var age = today.getFullYear() - birthDate.getFullYear();
    var m = today.getMonth() - birthDate.getMonth();
    if (m < 0 || (m === 0 && today.getDate() < birthDate.getDate())) 
    {
        age--;
    }
    return age;
}<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript program to calculate age</title>
</head>
<body>

</body>
</html>

calculate Age using Javascript
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