Question

I’m writing a function that reads a postfix expression in the form of a string and computes it accordingly.

Is there a simple way to convert the character of an arithmetic operator to the arithmetic operator itself in C++?

Answer 1

Assuming that this is for the classic RPN programming exercise, the simplest solution is to use a switch statement:

char op = ...    
int lhs = ...
int rhs = ...
int res = 0;
switch(op) {
    case '+':
        res = lhs + rhs;
    break;
    case '-':
        res = lhs - rhs;
    break;
    case '*':
        res = lhs * rhs;
    break;
    case '/':
        res = lhs / rhs;
    break;
    case '%':
        res = lhs % rhs;
    break;
}