C#四种Eval测试结果：不要用CodeDom做大批量的表达式四则运算

return 0;

}

Object qswhEval1(string Expression){

/*************(qiushuiwuhen 2002-12-14)****************/

Stack nArr=new Stack(),oArr=new Stack();

int j=0;

Double a=0,b=0;

string w="";

char o;

MatchCollection arr=Regex.Matches(Expression.Replace(" ","")+"#",@"(((?<=(^|\())-)?\d+(\.\d+)?|\D)");

oArr.Push('#');

w=Convert.ToString(arr[j++]);

while(!(w=="#"&&Convert.ToString(oArr.Peek())=="#")){

if("+-*/()#".IndexOf(w)!=-1){

switch(Precede(oArr.Peek().ToString(),w)){

case "<":

oArr.Push(w);

w=Convert.ToString(arr[j++]);

break;

case "=":

oArr.Pop();

w=Convert.ToString(arr[j++]);

break;

case ">":

o=Convert.ToChar(oArr.Pop());

b=Convert.ToDouble(nArr.Pop());

a=Convert.ToDouble(nArr.Pop());