JavaScript Validation on Variables by the type and size

Question

<form class="form-horizontal" name="f2" id="regisform" method="post" onsubmit="return false;" role="form">
    <div class="form-group">
        <label for="inputpcode3" class="col-sm-2 control-label">Pincode</label>
        <div class="col-lg-3">
            <input type="text" name="txtpcode1" class="form-control" id="inputpcode3" placeholder="pincode">
        </div>
    <input type="submit" name="submit" id="regisBtn" class="btn btn-primary" value="Registration">
</form>

The above represents the form. when the submit button pressed the following javascript will fire:

$(document).ready(function(){
    $("#regisBtn").click(function(){
        var pincode=$("#inputpcode3").val();

        if(pincode){
            //validation for pincode to check whether the pincode is only numeric or not and the size must be 6 only
        }
        else
        {
            alert("wrong");
        }
    });
});

as the javascript represent i wnt to that validation and display alert box whether that string contains only numbers or not and the size must be fixed of 6 length. and also show if we want to check whether the string contains only alphabets or not? Thanks.

Answer 1

You can use regular expressions to check your requirement:

if(/^\d{6}$/.test(pincode)){
    // Passed
}

Regex101 does a good job of explaining exactly what it means:

Answer 2

A Regular Expression, as said above, is probably your best bet...

/^[0-9]*$/

This checks your string and validates only if there are numbers present.

Also to check length is just a matter of if($(this).val().length > 6) { doSomethingElse() || disable Submit Button } if($(this).val().length > 6) { doSomethingElse() || disable Submit Button }

Check out this awesome online resource: (Really helps clarify) http://www.regextester.com/21