Java: Get the first and last elements in a tree set

Last update on March 12 2025 13:32:45 (UTC/GMT +8 hours)

Write a Java program to get the first and last elements in a tree set.

Sample Solution:

Java Code:

import java.util.TreeSet;
  public class Exercise5 {
  public static void main(String[] args) {
  TreeSet<String> tree_set = new TreeSet<String>();
  tree_set.add("Red");
  tree_set.add("Green");
  tree_set.add("Orange");
  tree_set.add("White");
  tree_set.add("Black");
  System.out.println("Tree set: ");
  System.out.println(tree_set);

   // Find first element of the tree set
    Object first_element = tree_set.first();
    System.out.println("First Element is: "+first_element);
 
    // Find last element of the tree set
    Object last_element = tree_set.last();
    System.out.println("Last Element is: "+last_element);
 }
}

Sample Output:

Tree set:                                                              
[Black, Green, Orange, Red, White]                                     
First Element is: Black                                                
Last Element is: White 

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to retrieve the first and last elements of a TreeSet using first() and last() methods, and print them.
• Write a Java program to compare the first and last elements of a TreeSet and determine if they satisfy a custom condition.
• Write a Java program to use a TreeSet’s iterator to get the first element and descendingIterator() to get the last element.
• Write a Java program to remove the first element using pollFirst() and the last element using pollLast(), then print the updated set.

Java Code Editor:

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