Java TreeSet higher() Method

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Description

The Java TreeSet higher(E e) method is used to return the least element in this set strictly greater than the given element, or null if there is no such element.

Declaration

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

public E higher(E e)

Parameters

e − This is the the value to be matched.

Return Value

The method call returns the least element greater than e, or null if there is no such element.

Exception

• ClassCastException − This exception is thrown if the specified element cannot be compared with the elements currently in the set.

• NullPointerException − if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements.

Getting Least Element Greater Than Given Element from the TreeSet of Integer Example

The following example shows the usage of Java TreeSet higher() method to get the least element in this set strictly greater than the given element in the treeset. We've created a TreeSet object of Integer. Then few entries are added using add() method and related value is printed using higher() method.

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(12);
      treeset.add(11);
      treeset.add(16);
      treeset.add(15);

      // getting the higher value for 13
      System.out.println("Higher value of 13: "+treeset.higher(13));   
   }       
}

Output

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

Higher value of 13: 15 

Getting Least Element Greater Than Given Element from the TreeSet of String Example

The following example shows the usage of Java TreeSet higher() method to get the least element in this set strictly greater than the given element in the treeset. We've created a TreeSet object of String. Then few entries are added using add() method and related value is printed using higher() method.

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("F");
      treeset.add("B");
      treeset.add("E");
      treeset.add("G");

      // getting the higher value for C
      System.out.println("Higher value of C: "+treeset.higher("C"));   
   }       
}

Output

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

Higher value of C: E

Getting Least Element Greater Than Given Element from the TreeSet of Object Example

The following example shows the usage of Java TreeSet higher() method to get the least element in this set strictly greater than the given element in the treeset. We've created a TreeSet object of String. Then few entries are added using add() method and related value is printed using higher() method.

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"));

      // getting the higher value for Adam
      System.out.println("Higher value of Adam: "+treeset.higher(new Student(3, "Adam")));   
   }       
}
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.

Higher value of Adam: [ 4, Julia ]