State Pattern

• we create objects which represent various states and a context object whose behavior varies as its state object changes.
• If we have to change the behavior of an object based on its state, we can have a state variable in the Object. Then use if-else condition block to perform different actions based on the state. State design pattern is used to provide a systematic and loosely coupled way to achieve this through Context and State implementations.

Reference

• tutorialspoint:State
• journaldev:State
• geeksforgeeks:State
• iluwatar:State