web前端：将前端页面中获取的字符串转换成整数

function numsOfQYZH(){
        var jccs = $("#JCCS").val();
        if(jccs=="090049"||jccs=="090050"||jccs=="090039"){
            return 2;
        }else{
            return 3;
        }
    }

function numOfTables() {
        var sysl = parseInt($("#SYSL").val());
        var table_num = numsOfQYZH();
        var nums = sysl*table_num;