c# 、js 字符串转换成逻辑表达式

C# 字符串转逻辑表达式

        /// <summary>
        /// 包含括号的逻辑表达式处理
        /// </summary>
        /// <param name="str">包含括号或未包含括号的字符串表达式 1>0&&(3<4)&&(5>4)</param>
        /// <returns></returns>
        public bool ExpressionWithParentheseResult(string str)
        {
            bool result = false;
            //首先判断括号，有多少个
            string[] parentheses = str.Split('(');
            //创建表达式判断函数
            DataTable dt = new DataTable();
            //有括号的情况
            if (parentheses.Length > 1)
            {
                //先判断括号里面的
                for (int parenthesesIndex = 1; parenthesesIndex < parentheses.Length; parenthesesIndex++)
                {
                    //括号里面的内容
                    string ParenthData = parentheses[parenthesesIndex].Split(')')[0];
                    //进行替换(括号结果替换整个括号的内容)
                    string reParenth = "(" + ParenthData + ")";
                    str = str.Replace(reParenth, ExpressionResult(ParenthData).ToString());
                }
            }
            result = ExpressionResult(str);
            return result;
        }

        /// <summary>
        /// 非括号表达式处理
        /// </summary>
        /// <param name="logicStr">逻辑表达式如 1<2&&3>4</param>
        /// <param name="val"></param>
        /// <returns></returns>
        public  bool ExpressionResult(string logicStr)
        {
            bool result = false;
            DataTable dt = new DataTable();
            var data = Regex.Split(logicStr, @"\|\||&&", RegexOptions.IgnoreCase);
            var operatorStr = "||";
            for (int i = 0; i < data.Length; i++)
            {
                if (i != 0)
                {
                    operatorStr = logicStr.Substring(logicStr.IndexOf(data[i - 1]) + data[i - 1].Length, 2);
                }
                var res = (bool)dt.Compute(data[i], "");
                result = LogicEx(result, res, operatorStr);
            }
            return result;
        }

        /// <summary>
        /// 逻辑判断
        /// </summary>
        /// <param name="a1">结果1</param>
        /// <param name="a2">结果2</param>
        /// <param name="re">运算符</param>
        /// <returns></returns>
        public  bool LogicEx(bool a1, bool a2, string re)
        {
            bool result = false;
            switch (re)
            {
                case "&&": result = a1 && a2; break;
                case "||": result = a1 || a2; break;
            }
            return result;
        }

JS 字符串转表达式处理

var a=1;
var b=2;
var result= eval("a == null && b != 5")
//结果为false