js调用正则表达式

        //验证是否为正整数
        function isPositiveInteger(s) {
            var re = /^[0-9]+$/;
            return re.test(s);
        }
 
        if (exchangeCount === "" || exchangeCount === "0" || Number(exchangeCount) === NaN || !isPositiveInteger(exchangeCount))// Number(exchangeCount) === NaN ,如果是非值类型返回值即为NAN

           {
                $("#ValidateExchangeCount").text("请输入正确的换货数量");
                validateResult = false;
            } else 
           {
                $("#ValidateExchangeCount").text("");
            }