Java TreeSet subSet() Method

The subSet() method of TreeSet class is used to get the set elements which are in the range from fromElement to toElement.

Syntax:

public SortedSet<E> subSet(E fromElement,
                           E toElement)

Parameter:

fromElement- the Minimum endpoint of the returned set

toElement- the Maximum endpoint of the returned set.

Return:

It returns the set which range from fromElement to toElement.

Throws:

ClassCastException: Throws exception when the range from fromElement to toElement cannot be compared to elements present in the set.

NullPointerException: Throws exception when fromElement to toElement is null.

IllegalArgumentException: Throws exception when fromElement is greater than toElement, or out of range.

Example 1

import java.util.*;
public class JavaTreeSetSubSetExample1
{
  public static void main(String as[]){
  TreeSet <Integer>obj = new TreeSet<Integer>();
  TreeSet <Integer>obj1 = new TreeSet<Integer>();
  obj.add(4);	
  obj.add(6);
  obj.add(9);
  obj.add(12);
  obj.add(18);
  System.out.println("TreeSet: " +obj);
  obj1=(TreeSet<Integer>) obj.subSet(6,12);
  System.out.println("Elements of  TreeSet: " +obj1);
  }
}

Output:

TreeSet: [4, 6, 9, 12, 18]
Elements of  TreeSet: [6, 9]

Example 2

import java.util.*;
public class JavaTreeSetsubSetExample2
{
  public static void main(String as[]){
  TreeSet <String> obj = new TreeSet<String>();
  TreeSet <String> obj1 = new TreeSet<String>();
  obj.add("B");	
  obj.add("9");
  obj.add("1");
  obj.add("b");
  obj.add("A");
  obj.add("a");
  obj.add("6");
  obj.add("3");
  System.out.println("TreeSet: " +obj);
obj1=(TreeSet<String>) obj.subSet("3","a");
  System.out.println("Elements of  TreeSet: " +obj1);
  }
}

Output:

TreeSet: [1, 3, 6, 9, A, B, a, b]
Elements of  TreeSet: [3, 6, 9, A, B]

Example 3

import java.util.*;
class student{  
    private int roll_no;  
    private String name;  
    private String sem; 
    private String branch;
    public student(int roll_no, String name, String sem,String branch ) {  
        this.roll_no = roll_no;  
        this.name = name;  
        this.sem = sem;  
        this.branch=branch;
    }  
   
    public String toString(){  
       return roll_no+"  " +name+"  "+sem+" "+branch;  
    }  
}  
public class student_1 {  
    public static void main(String[] args) {  
        student stu1 = new student(001, "Shristee", "III", "B.tech(C.S)");  
        student stu2 = new student(002, "Shweta  ", "I  ", "B.tech(I.t)");  
        student stu3 = new student(003, "Suma    ", "II ", "Msc(I.t)");  
        student stu4 = new student(004, "Dolly   ", "V  ", "MCA");
          TreeSet <String> obj = new TreeSet<>();
           TreeSet <String> obj1 = new TreeSet<>();
          String s1=stu1.toString();
          String s2=stu2.toString();
          String s3=stu3.toString();
          String s4=stu4.toString();
         obj.add(s1);  
        obj.add(s2);  
        obj.add(s3);  
        obj.add(s4);
        System.out.println("Elements in TreeSet: ");
        for (String xyz : obj) {  
            System.out.println(xyz);  
        }
        obj1=(TreeSet<String>) obj.subSet(s2,s4);
  System.out.println("Elements of  TreeSet: " +obj1);
    }  
}  

Output:

Elements in TreeSet: 
1  Shristee  III B.tech(C.S)
2  Shweta    I   B.tech(I.t)
3  Suma      II  Msc(I.t)
4  Dolly     V   MCA
Elements of  TreeSet: [2  Shweta    I   B.tech(I.t), 3  Suma      II  Msc(I.t)]