It's possible to evaluate a string as a mathematical expression?C++3.1

[15963]

Hello,

I want to ask if it's possible to evaluate a string in borland c++3.1.
For instance, everytime I start the program I read a string (ex. STR="sin(2*x)+x*x+90&quot, and a value for x(ex. x=10).
It's possible to use the string STR as a macro(or to use it in a file,or in any other way) that would evaluate the string STR as a function with the argument x, and would return his value?
(Just like the function below...)

float STR(int x)
{
return sin(2*x)+x*x+90;
}


Thanks

 

[cyprus106]

You'd probably have to create that macro but yes, its possible. You'll have to do the work but of you use an array or two and a few keys it shouldn't be too hard. Cyprus

 

[gRegister]

seems you would need to create a stack to do postfix polish notation processing

 

[Zyrenthian]

Yep... the stack would be my suggestion. Actually of them. One for values and one for expressions. Then when you pop you do things correctly

value.pop op.pop value.pop
x + y


Matt