layout | title | folder | permalink | categories | tags | |||
---|---|---|---|---|---|---|---|---|
pattern |
Singleton |
singleton |
/patterns/singleton/ |
Creational |
|
Ensure a class only has one instance, and provide a global point of access to it.
Use the Singleton pattern when
- there must be exactly one instance of a class, and it must be accessible to clients from a well-known access point
- when the sole instance should be extensible by subclassing, and clients should be able to use an extended instance without modifying their code
- the logging class
- managing a connection to a database
- file manager