Question

I have an input box:

<input class="longboxsmall" type="text" name="number" value=""/>

And I want to disallow the number 0 being the first number entered in the box how can I do this??? Can I use Jquery??

Answer 1

$(".longboxsmall").keyup(function(){
    var value = $(this).val();
    value = value.replace(/^(0*)/,"");
    $(this).val(value);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input class="longboxsmall" type="text" name="number" value=""/>

JS

$(".longboxsmall").keyup(function(){
    var value = $(this).val();
    value = value.replace(/^(0*)/,"");
    $(this).val(value);
});

HTML

<input class="longboxsmall" type="text" name="number" value=""/>

Try in jsfiddle.

---

IT’s good to intercept another events, like blur, change, focusout, etc.
See jquery.
Tks @Simen Echholt.

---

Explanation:

$(".longboxsmall").keyup

Jquery take every element with class longboxsmall and are ready to call a function on onkeyup event.

var value = $(this).val();
value = value.replace(/^(0*)/,"");
$(this).val(value);

This function uses a regex to replace every 0 in begin (^) of value.