Grading system in C++

Question

So this is my C++ question :

Write a program that translates a letter grade into a number grade. Letter grades are A, B, C, D and F, possibly followed by + or -. Th

Answer 1

I'd deal with each character in turn. You know that the first one should be a letter grade, so you look at that one first, and you could just use a switch statement like you've already got for that.

uint value = 0;
char grade_letter = grade[0];

switch (grade_letter) {
    // assign value as appropriate
}

Then, if the second character exists, check if it's a + or a - and modify the value you got from the switch statement accordingly.

if (grade.length() > 1) {
    char modifier = grade[1];
    switch (modifier) {
        case '+': value += 0.3;
        // etc.
    }
}

Before all that of course, you'll want to check for the special case of A+ and skip everything else.

An alternative approach would be to replace the switch statements with lookups in a previously-prepared data structure, something like a std::map, which, even if the initialisation code prepared it from hardcoded data, would open the way to loading the grade information from a configuration file or database at some point in the future. Special-casing A+ in that case becomes slightly trickier though.