What are the common mistakes in implementing the Singleton pattern?

What are the common mistakes in implementing the Singleton pattern?

Some common mistakes include not making the constructor private, failing to handle multithreading, and not ensuring lazy initialization.

Can you explain why making the constructor private is important?

Making the constructor private prevents other classes from instantiating the Singleton class, ensuring only one instance exists.

What issues can arise from not handling multithreading properly?

Without proper synchronization, multiple threads might create multiple instances of the Singleton, violating its purpose.

What is lazy initialization, and why is it useful?

Lazy initialization defers the creation of the Singleton instance until it's needed, which can improve performance and resource usage.