- HashSet it is based on HashTable
- Duplicate object not allowed in HashSet.
- Insertion order is not preserved.
- It is based on HashCode of object.
- It allows Null Insertion.
- Heterogeneous object are allowed
- Internally implements Serializable Clonable Interface
- Not implements RandomAccess Interface
- HashSet is the best choice of frequent operation in the search operation
- It is based on LinkedList+HashTable
- preserved insertion oreder
- duplicate object not allowed
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