Mutable and Immutable in Java

In Java, mutable and immutable refer to whether an object’s state (its data fields) can be changed after it is created.

1. Mutable Objects:
   • The state of a mutable object can be modified.
   • Examples: Instances of classes like StringBuilder, ArrayList, or user-defined classes where fields can be updated.
   • Mutability is useful for situations where object updates are required, like collections or buffers.
2. Immutable Objects:
   • The state of an immutable object cannot be modified after creation.
   • Example: String, Integer, and BigDecimal are immutable classes.
   • Benefits: Thread safety, simplicity in design, and consistency.

Proper usage of mutable or immutable objects depends on the application’s requirements.