C-Eclipse CDT-有效的调试+什么是更好的代码（指向函数的指针）？

Question

I'm a new C programmer and I'm writing some data structures for homework. I have two questions here.

1. We see a lot of examples of C's function-pointers, usually used to save code duplication. I messed around with this function, which I initially wrote:

(The constants we're pre #defined. Indentation is off, too).

    static PlayerResult playerCheckArguments(const char* name, int age,
    int attack, int defense) {
    PlayerResult result = PLAYER_SUCCESS;
    if (!name) {
    result =  PLAYER_NULL_ARGUMENT;
    } else if (strlen(name) > PLAYER_MAX_NAME_LENGTH) {
    result =  PLAYER_NAME_TOO_LONG;
    } else if (invalidAge(age)) {
    result = PLAYER_INVALID_AGE;
    } else if (invalidAttack(attack)) {
    result = PLAYER_INVALID_ATTACK;
    } else if (invalidDefense(defense)) {
    result =  PLAYER_INVALID_DEFENSE;
    }
    return result;
}

until I got this ghoul:

    static PlayerResult playerCheckArguments(const char* name, int age, int attack,
    int defense) {
void* arguments[PLAYER_NUM_OF_PAREMETERS] = { name, &age, &attack, &defense };
PlayerResult (*funcArray[PLAYER_NUM_OF_PAREMETERS])(
        int) = {&invalidName, &invalidAge, &invalidAttack, &invalidDefense };
PlayerResult result = PLAYER_SUCCESS;
for (int i = 0;
        i < PLAYER_NUM_OF_PAREMETERS && result == PLAYER_SUCCESS; i++) {
    PlayerResult (*func)(int) = funcArray[i];
    void* key = arguments[i];
    result = func(key);
}
return result;

My first question being - is there any reason why I should use/write the second function over the other, and generally try to use such "sophistications" which obviously lessen the code's clarity and/or simplicity?

now, for my second question: As you may have noticed, I am using a lot of local variables for the purpose of easier debugging. this way, I can see all relevant evaluations and efficiently monitor the program as it runs. Is there any other way to display expressions made in a function other than using local variables?

Thanks very much!

return 0 ;-)

Answer 1

Since your question is tagged coding style, I'll just say, the first is definitely preferred. The reason is simple. Show the two functions to 200 programmers, 100 see the first, 100 see the second, and then record the average time it takes for the programmers to be able to describe what the function does. you'll absolutely, averaged over hundreds of programmers, find that the first wins every time.

So you would only do the second if perhaps you had 20+ different parameters to check, and even then there are cleaner ways to do it. I don't believe you'd see any speed increase for the second one either.

Answer 2

Clarity is far more important than cleverness. The harder it is to figure out the harder it is to get right, and to debug when you don't.

There is nothing wrong with using local variables for clarity or debugging. There is an ole saw that goes "Avoid the sin of premature optimization". Make your code as simple and as clear as you can. If you then find that isn't enough work to add as little complexity as needed to get the job done.