Collection vs Collections
- Collection is an interface that represents a group of objects
- Collections is a utility class that provides helper methods for collections
Core Difference
| Point | Collection | Collections |
|---|---|---|
| Type | Interface | Utility class |
| Package | java.util | java.util |
| Purpose | Store and manage elements | Operate on collections |
| Contains methods | add, remove, size, iterator | sort, reverse, shuffle |
| Can be instantiated | ❌ No | ❌ No |
| Used for | Data structure | Helper operations |
Collection
Collection is the root interface of the Java Collections Framework.
Characteristics
- Represents a group of objects
- Provides basic operations like add, remove, iterate
- Parent of:
- List
- Set
- Queue
Collections
Collections is a utility class with only static methods.
Characteristics
- Cannot be instantiated
- Used to perform operations on collections
- Provides algorithms and wrappers
Common methods
sort()reverse()shuffle()synchronizedList()unmodifiableList()
Collection is an interface used to store groups of objects, whereas Collections is a utility class that provides static methods to operate on collections.