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

This could work:

$('input#foo').keyup(function(e) {
    if((this.value+'').match(/^0/)) {
        this.value = (this.value+'').replace(/^0+/g, '');
    }    
});

The only thing that could bother you with this solution is that zero is displayed for a second and then deleted, since we are using keyup event.

A quick demo