NSUInteger与NSInteger的实现中参数类型冲突

Question

I have a problem with an error about conflicting parameter types in implementation of NSUInteger vs NSInteger.

I have seen a lot of similar issues and it seems that the most frequent ones happen while defining the pointer with the * character.

Integer is a primitive type and I'm not using pointers at all, so where is the problem ?

- (void) guessNumber: (NSInteger)number withRange:(NSInteger)range{


    dispatch_queue_t queue = dispatch_queue_create("com.alex.guessnumber.queue", DISPATCH_QUEUE_SERIAL);


    dispatch_async(queue, ^{

        double startTime = CFAbsoluteTimeGetCurrent();

        NSInteger randomNumber;
        NSInteger range;

        while (randomNumber != number) {
            randomNumber = arc4random_uniform(range);
        }
        NSLog(@"Student %@ guessed number %d in %f", self.name, randomNumber, CFAbsoluteTimeGetCurrent() - startTime);
    });

}

Answer 1

arc4random_uniform返回uint32_t，其值从0到2 ^ 32-1。您尝试将其存储在NSInteger中，在32位系统上，该值的范围是-2 ^ 31至+ 2 ^ 31-1。这是行不通的。