Question

I am trying to validate a contact number field, with that I am not allowing any letters.

JS FILE

$(document).ready(function() {
    //var regex = /[^\d]/;
    var regex = /[^a-zA-Z]/;
    $('#contact_num').blur(function() {
        if(regex.test($(this).val()) == true) {
            alert('valid');
        } else {
            alert('invalid');
        }
    });
});​

HTML FILE

Contact Num: <input type="text" id="contact_num" />​

My regex here seems to return valid if the letters comes with the digits, which must be false.

DEMO

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Answer 1

You are only checking a single character, though you are very close. You need anchor characters on the side.

var regex = /^[^a-zA-Z]+$/;