为什么这个数组为对象计数返回0？

Question

我的阵列:

NSMutableArray *squareLocations;

CGPoint dotOne = CGPointMake(1, 1);
[squareLocations addObject:[NSValue valueWithCGPoint:dotOne]];

CGPoint dotTwo = CGPointMake(10, 10);
[squareLocations addObject:[NSValue valueWithCGPoint:dotTwo]];

CGPoint dotThree = CGPointMake(100, 100);
[squareLocations addObject:[NSValue valueWithCGPoint:dotThree]];

int num = [squareLocations count];

for (int i = 0; i < num; i++)
{
    NSValue *pointLocation = [squareLocations objectAtIndex:i];
    NSLog(@"%@", pointLocation);
}

当我要求squareLoctions对象计数时,它返回零？但就在上面要求计数我添加了三个NSValue对象??? 有人有主意吗？

Answer 1

您需要首先初始化数组

NSMutableArray *squareLocations = [[NSMutableArray alloc] init];