JSFiddle - React, Tailwind, and code Playground

HTML

<input class="order form-control vnumber" type="text" maxlength="1" name="Orderbox[]" required="true">
<input class="order form-control vnumber" type="text" maxlength="1" name="Orderbox[]" required="true">
<input class="order form-control vnumber" type="text" maxlength="1" name="Orderbox[]" required="true">
<input class="order form-control vnumber" type="text" maxlength="1" name="Orderbox[]" required="true">
<input class="order form-control vnumber" type="text" maxlength="1" name="Orderbox[]" required="true"> <span class="val"></span>

JavaScript

var arr = [];
$('.order').change(function () {
    arr.push($(this).val());
    if (arr.length > 1) {
        if (arr.AllValuesSame()) alert("Values are same");
    }
    var val = 0;
    $.each(arr, function () {
        val = parseInt(val) + parseInt(this);
    });
    $('.val').text(val);
});
Array.prototype.AllValuesSame = function () {
    if (this.length > 0) {
        for (var i = 1; i < this.length; i++) {
            if (this[i] !== this[0]) return false;
        }
    }
    return true;
}