Transforming a NSString @"123" in an (short)array[] = {1, 2, 3}?

I can't imagine a "clean" or efficient method of doing this.

I would like to transform a string of numbers like @"1234" into an array of shorts for a calculator pet project*.

I think of getting substrings and then the intValue of the substring but it sounds cumbersome and overkill. Would there be a more elegant way of doing it?

Thanks in advance!

* I know that there are more efficient ways to do maths and plenty of C libraries do this but it's for m开发者_StackOverflow社区y own education :-).

If I have this straight, you want to turn an NSString into a short array? This function assumes each character in the NSString is a separate short. Oh, and don't forget to free that array when you're done with it!

//Stephen Melvin <jinksys@gmail.com>
short *NSStringToShortArray(NSString *digits){

    int count = [digits length];

    short *shortArray = malloc(sizeof(short)*count);

    for(int i = 0; i<count; i++){
        shortArray[i] = (short)[digits characterAtIndex:i] - '0';
    }

    return shortArray;
}

A good calculator interface should take one string of characters as a single number then after the operation is selected it clears the field to accept the next number.

For example.

You type in 2 then hit the * button, the field clears and you type in 2 again and press = and get 4.

If you want the interface to accept an equation or a script then you should read up on parsing numeric equations.