NSPointerArray 奇怪的压缩

NSPointerArray是Foundation框架中的一个类，用于存储和管理Objective-C对象的数组。与NSArray和NSMutableArray类似，但它具有一些独特的特性。其中一个奇怪的特性是其压缩行为，本文将对这种奇怪的压缩进行详细介绍，并提供相关的案例代码。

objective-c
NSPointerArray *pointerArray = [NSPointerArray strongObjectsPointerArray];
// 向数组中添加对象
NSString *object1 = @"Object 1";
NSString *object2 = @"Object 2";
[pointerArray addPointer:(__bridge void * _Nullable)(object1)];
[pointerArray addPointer:(__bridge void * _Nullable)(object2)];
// 打印数组中的对象
for (NSUInteger i = 0; i < pointerArray.count; i++) {
    NSString *object = (__bridge NSString *)([pointerArray pointerAtIndex:i]);
    NSLog(@"Object at index %lu: %@", (unsigned long)i, object);
}
// 从数组中移除一个对象
[pointerArray removePointerAtIndex:0];
// 打印数组中的对象
for (NSUInteger i = 0; i < pointerArray.count; i++) {
    NSString *object = (__bridge NSString *)([pointerArray pointerAtIndex:i]);
    NSLog(@"Object at index %lu: %@", (unsigned long)i, object);
}
// 输出数组的容量和实际存储的对象数量
NSLog(@"Array capacity: %lu", (unsigned long)pointerArray.count);
NSLog(@"Array count: %lu", (unsigned long)pointerArray.allObjects.count);