Java: Find the numbers less than 7 in a tree set

Last update on March 12 2025 13:32:43 (UTC/GMT +8 hours)

Write a Java program to find numbers less than 7 in a tree set.

Sample Solution:

Java Code:

import java.util.TreeSet;
import java.util.Iterator;

  public class Exercise9 {
  public static void main(String[] args) {
 // creating TreeSet 
   TreeSet <Integer>tree_num = new TreeSet<Integer>();
   TreeSet <Integer>treeheadset = new TreeSet<Integer>();
     
   // Add numbers in the tree
   tree_num.add(1);
   tree_num.add(2);
   tree_num.add(3);
   tree_num.add(5);
   tree_num.add(6);
   tree_num.add(7);
   tree_num.add(8);
   tree_num.add(9);
   tree_num.add(10);
     
   // Find numbers less than 7
 treeheadset = (TreeSet)tree_num.headSet(7);  

   // create an iterator
   Iterator iterator;
   iterator = treeheadset.iterator();
     
   //Displaying the tree set data
   System.out.println("Tree set data: ");     
   while (iterator.hasNext()){
   System.out.println(iterator.next() + " ");
   }
   }    
}

Sample Output:

Note: Exercise9.java uses unchecked or unsafe operations.              
Note: Recompile with -Xlint:unchecked for details.                     
Tree set data:                                                         
1                                                                      
2                                                                      
3                                                                      
5                                                                      
6 

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to use the headSet() method on a TreeSet to extract all numbers less than 7 and print the resulting set.
• Write a Java program to filter a TreeSet using Java streams to collect numbers less than 7 into a new set.
• Write a Java program to iterate over a TreeSet and print only those numbers that are less than 7.
• Write a Java program to remove all elements greater than or equal to 7 from a TreeSet and then display the remaining elements.

Java Code Editor:

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