Disable zero as first letter in <input>

Question

Below code disables 0 as the first character in #foo.
However, you can bypass this by typing 123, then drag to select 123

Answer 1

I would handle the input, propertychange, and paste events. Then use regex to match for anything that begins with 0 and replace the current value with the value minus the leading 0.

http://jsfiddle.net/SeanWessell/5qxwpv6h/

$('input ').on('input propertychange paste', function (e) {
    var val = $(this).val()
    var reg = /^0/gi;
    if (val.match(reg)) {
        $(this).val(val.replace(reg, ''));
    }
});

Bug fix reported by Kevin/Updated per recommendations of canon:

http://jsfiddle.net/SeanWessell/5qxwpv6h/2/

$('input').on('input propertychange paste', function (e) {
    var reg = /^0+/gi;
    if (this.value.match(reg)) {
        this.value = this.value.replace(reg, '');
    }
});