Js validates a simple example of an integer plus a reserved decimal point

function validateNum(obj) {
    //Positive integers (cache is used here)
    var number = obj.data(validate).number;
    //Decimal point (cache here)
    var decimal = obj.data(validate).decimal;
    //Dynamic basic verification regularization
    eval("var reg = /^[0-9]{0," + number + "}([.]?[0-9]{0," + decimal + "})$" + "/g;");
    var value = obj.val();
    var maxnumlen = number + decimal + 1; //Maximum length + 1(decimal point)
    if (!reg.test(obj.val())) return false;
    //The maximum length is the length of the current value and the value has no "."
    if (maxnumlen == value.length && value.indexOf('.') <= 0) {
        return false;
    }
    //Try to get the index of ".
    var valueindexof = value.indexOf('.');
    if (valueindexof > 0) {
        //If the last bit of the "." index is empty, then false is returned
        if (value.charAt(valueindexof + 1) == "") {
            return false;
        }
    }
    //The split value is easy to determine before and after
    var valuesplit = value.split('.');
    //If the length of the value is greater than the length of the defined positive integer
    if (value.length > number) {
        if (valuesplit.length == 1) {
            return false;
        }
        //Maximum length - defined length greater than the maximum length is false.
        if (maxnumlen - number >= maxnumlen) {
            return false;
        }
    }
    return true;
}

After the element is cached with a validate object, it is called.
Definition:
$(" # example "). The data (the "validate", {a decimal number: 2:2});
Call:
ValidateNum ($(" # example));