remove character from input field while user is typing (keyup)
The issue is because you're not setting the value of the input, only getting it and making the replacement and doing nothing with the resulting string. Try this:
$(function() {
$(".remove-sharp").on("keyup", function(event) {
var value = $(this).val();
if (value.indexOf('#') != -1) {
$(this).val(value.replace(/\#/g, ""));
}
})
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" class="remove-sharp" />