How Can I Validate That Someone Is Over 18 From Their Date Of Birth?

I am doing validation for Driver's Date of birth, it should be minimum of 18 from the current date. var Dates = $get('<%=ui_txtDOB.ClientID %>'); var Split = Dates.value.s

Solution 1:

I think a better alternative would be to calculate the age of the user, and use that in your if statement.

See this SO answer on how to do just that:

Calculate age in JavaScript

Solution 2:

Try this.

var enteredValue = $get('<%=ui_txtDOB.ClientID %>');;
var enteredAge = getAge(enteredValue.value);
if( enteredAge > 18 ) {
    alert("DOB not valid");
    enteredValue.focus();
    returnfalse;
}

Using this function.

functiongetAge(DOB) {
    var today = newDate();
    var birthDate = newDate(DOB);
    var age = today.getFullYear() - birthDate.getFullYear();
    var m = today.getMonth() - birthDate.getMonth();
    if (m < 0 || (m === 0 && today.getDate() < birthDate.getDate())) {
        age--;
    }    
    return age;
}

Demo here: http://jsfiddle.net/codeandcloud/n33RJ/

Solution 3:

<script>functiondobValidate(birth) {


        var today = newDate();
        var nowyear = today.getFullYear();
        var nowmonth = today.getMonth();
        var nowday = today.getDate();
        var b = document.getElementById('<%=TextBox2.ClientID%>').value;



        var birth = newDate(b);

        var birthyear = birth.getFullYear();
        var birthmonth = birth.getMonth();
        var birthday = birth.getDate();

        var age = nowyear - birthyear;
        var age_month = nowmonth - birthmonth;
        var age_day = nowday - birthday;


        if (age > 100) {
            alert("Age cannot be more than 100 Years.Please enter correct age")
            returnfalse;
        }
        if (age_month < 0 || (age_month == 0 && age_day < 0)) {
            age = parseInt(age) - 1;


        }
        if ((age == 18 && age_month <= 0 && age_day <= 0) || age < 18) {
            alert("Age should be more than 18 years.Please enter a valid Date of Birth");
            returnfalse;
        }
    }



</script>

Solution 4:

After looking at various methods of doing this, I decided the simplest way was to encode the dates as 8-digit integers. You can then subtract today's code from the DOB code and check if it's greater than or equal to 180000.

functionisOverEighteen(year, month, day) {
  var now = parseInt(newDate().toISOString().slice(0, 10).replace(/-/g, ''));
  var dob = year * 10000 + month * 100 + day * 1; // Coerces strings to integersreturn now - dob > 180000;
}

Solution 5:

letTODAY = newDate(Date.now());
letEIGHTEEN_YEARS_BACK = newDate(newDate(TODAY).getDate() + "/" + newDate(TODAY).getMonth() + "/" + (newDate(TODAY).getFullYear() - 18));
letUSER_INPUT = newDate("2003/12/13");
// Validate Nowlet result = EIGHTEEN_YEARS_BACK > USER_INPUT// true if over 18, false if less than 18

I think this is the closest possible way to check.