Java TreeSet last() Method

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Description

The Java TreeSet last() method is used to return the last (highest) element currently in this set.

Declaration

Following is the declaration for java.util.TreeSet.last() method.

public E last()

Parameters

NA

Return Value

The method call returns the last (highest) element currently in this set.

Exception

NoSuchElementException − This exception is thrown if this set is empty.

Getting Last Elememt of a TreeSet of Integer Example

The following example shows the usage of Java TreeSet last() method to get the last (highest) element currently in this set. We've created a TreeSet object of Integer. Few entries are added using add() method and last/highest element is retrieved using last() method and printed.

package com.tutorialspoint;

import java.util.TreeSet;

public class TreeSetDemo {
   public static void main(String[] args) {

      // creating a TreeSet 
      TreeSet<Integer> treeset = new TreeSet<>();

      // adding in the tree set
      treeset.add(1);
      treeset.add(13);
      treeset.add(17);
      treeset.add(2);

      // displaying the last highest element
      System.out.println("Last highest element: "+treeset.last());    
   }    
}

Output

Let us compile and run the above program, this will produce the following result.

Last highest element: 17 

Getting Last Elememt of a TreeSet of String Example

The following example shows the usage of Java TreeSet last() method to get the last (highest) element currently in this set. We've created a TreeSet object of String. Few entries are added using add() method and last/highest element is retrieved using last() method and printed.

package com.tutorialspoint;

import java.util.TreeSet;

public class TreeSetDemo {
   public static void main(String[] args) {

      // creating a TreeSet 
      TreeSet<String> treeset = new TreeSet<>();

      // adding in the tree set
      treeset.add("A");
      treeset.add("D");
      treeset.add("C");
      treeset.add("B");

      // displaying the last highest element
      System.out.println("Last highest element: "+treeset.last());    
   }    
}

Output

Let us compile and run the above program, this will produce the following result.

Last highest element: D 

Getting Last Elememt of a TreeSet of Object Example

The following example shows the usage of Java TreeSet last() method to get the last (highest) element currently in this set. We've created a TreeSet object of Student. Few entries are added using add() method and last/highest element is retrieved using last() method and printed.

package com.tutorialspoint;

import java.util.TreeSet;

public class TreeSetDemo {
   public static void main(String[] args) {

      // creating a TreeSet 
      TreeSet<Student> treeset = new TreeSet<>();

      // adding in the tree set
      treeset.add(new Student(1, "Robert"));
      treeset.add(new Student(2, "Julie"));
      treeset.add(new Student(3, "Adam"));
      treeset.add(new Student(4, "Julia"));

      // displaying the last highest element
      System.out.println("Last highest element: "+treeset.last());    
   }    
}
class Student implements Comparable<Student> {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
   
   @Override
   public boolean equals(Object obj) {
      Student s = (Student)obj;
      return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name);
   }

   @Override
   public int compareTo(Student student) {
      return this.rollNo - student.rollNo;
   }
}

Output

Let us compile and run the above program, this will produce the following result.

Last highest element: [ 4, Julia ]