I'm currently writing a program that takes in a function such as ( 7x+19 ) and I need to evaluate the function that user inputs at range of numbers. I've got the loop figured out to loop through my desired numbers, but I don't know what to call the function when the user cin>>function. Should it be a char, string, int, double? Because later I'll need to call function and mult. it by lets say 3, or 5, or 12, etc? So what should I do to accomplish what I need to get done, I'm kind of stuck on this one. I'm kind of a beginner.