The subSet() method of SortedSet interface in Java is used to return a view of the portion of this set whose elements range from fromElement, inclusive, to toElement, exclusive.
- The set returned by this method is backed by this set, so changes in the returned set are reflected in this set, and vice-versa.
- The set returned by this method supports all optional set operations that this set supports.
Note: The set returned by this method will throw an IllegalArgumentException if an attempt is made to insert an element outside its range.
Syntax:
SortedSet subSet(E fromElement,
E toElement)
Where, E is the type of element maintained by this Set.
Parameters: This function accepts two parameters fromElement and toElement which represent the low endpoint (inclusive) and high endpoint (exclusive) of the returned set.
Return Value: It returns the elements which in range between fromElement and toElement passed as argument.
Exceptions:
- ClassCastException : It throws a ClassCastException if fromElement is not compatible with this set’s comparator (or, if the set has no comparator, if fromElement does not implement Comparable).
- NullPointerException : It throws a NullPointerException if the parameter fromElement is null.
- IllegalArgumentException : It throws an IllegalArgumentException this set itself has a restricted range, and the parameter fromElement lies outside the bounds of the range.
Below programs illustrate the above method:
Program 1:
// A Java program to demonstrate// working of SortedSetimport java.util.SortedSet;import java.util.TreeSet;  public class Main {    public static void main(String[] args)    {        // Create a TreeSet and inserting elements        SortedSet<Integer> s = new TreeSet<>();          // Adding Element to SortedSet        s.add(1);        s.add(5);        s.add(2);        s.add(3);        s.add(9);          // Returning the set with elements        // ranging between the passed value        System.out.print("Elements range between 2 and 9 in set are : "                         + s.subSet(2, 9));    }} |
Elements range between 2 and 9 in set are : [2, 3, 5]
Program 2:
// A Java program to demonstrate// working of SortedSetimport java.util.SortedSet;import java.util.TreeSet;  public class Main {    public static void main(String[] args)    {        // Create a TreeSet and inserting elements        SortedSet<String> s = new TreeSet<>();          // Adding Element to SortedSet        s.add("Geeks");        s.add("For");        s.add("Geeks");        s.add("Code");        s.add("It");          // Returning the set with elements        // ranging between the passed value        System.out.print("Elements between C and G in set is : "                         + s.subSet("C", "G"));    }} |
Elements between C and G in set is : [Code, For]
Reference: https://docs.oracle.com/javase/10/docs/api/java/util/SortedSet.html#subSet(E)
