Explain about Set and their types in a collection?
Set cares about uniqueness. It doesn’t allow duplications. Here “equals ( )” method is used to determine whether two objects are identical or not.
Hash Set:
- Unordered and unsorted.
- Uses the hash code of the object to insert the values.
- Use this when the requirement is “no duplicates and don’t care about the order”.
Example:
public class Fruit {
public static void main (String[ ] args){
HashSet<String> names = new HashSet <=String>( ) ;
names.add(“banana”);
names.add(“cherry”);
names.add(“apple”);
names.add(“kiwi”);
names.add(“banana”);
System.out.println (names);
}
}
Output:
[banana, cherry, kiwi, apple]
Doesn’t follow any insertion order. Duplicates are not allowed.