create random integers for quiz using plist

Question

I would like to have user click on a button to generate a ten-question quiz in the form of \"a +/- b = c\" where the values for a and b are from +10 to -10 and are randomly assi

Answer 1

Instead of using a NSDictionary, use NSArray if your keys are just numbers. You could then do

NSString *randomString = [array objectAtIndex:(arc4random() % [array count])]; 

to pick a random element.

However, I would really advice against looking it up in a plist if it's just different combinations of random numbers. Writing out all those combinations by hand is just a waste of time. That's what computers are for!

Old, but still relevant answer:

To generate a random number between -10and 10:

int a = (arc4random() % 21) - 10;

You could also make a function like this:

int randomIntegerInRange(int min, int max)
{
    int range = max - min + 1;
    return min + arc4random() % range;
}