What potential difficulties or disadvantages may arise when implementing lazy initialization?

Lazy initialization is an approach where an object or value is created only when it is first needed. When implementing lazy initialization, the following issues may arise:

• Thread safety: if multiple threads try to initialize the resource simultaneously, race conditions can occur, leading to multiple instances or errors.
• Code complexity: adding checks and synchronization for lazy initialization can make the code less readable.
• Delayed errors: errors during initialization will appear not immediately, but at the first access, which can complicate debugging.
• Memory: if the object is heavy and rarely used, lazy creation helps save resources, but if the object is needed almost always, laziness can only complicate logic.

In iOS, when using lazy properties (lazy var), it is important to consider that they are not thread-safe by default, so additional synchronization mechanisms are needed when accessed from multiple threads.