Java: Get the least key strictly greater than the given key

Last update on March 12 2025 13:34:03 (UTC/GMT +8 hours)

Write a Java program to get the least key strictly greater than the given key. Return null if there is no such key.

Sample Solution:-

Java Code:

import java.util.*;
import java.util.Map.Entry;  
public class Example15 {  
       public static void main(String args[]){  
  
    // Create a tree map
   TreeMap< Integer, String > tree_map1 = new TreeMap< Integer, String >();      
  
  // Put elements to the map 
  tree_map1.put(10, "Red");
  tree_map1.put(20, "Green");
  tree_map1.put(40, "Black");
  tree_map1.put(50, "White"); 
  tree_map1.put(60, "Pink"); 
    
      System.out.println("Orginal TreeMap content: "+tree_map1);
	  System.out.println("Checking the entry for 10: ");
      System.out.println("Key(s): "+tree_map1.higherEntry(10));  
	  System.out.println("Checking the entry for 20: ");
      System.out.println("Key(s): "+tree_map1.higherEntry(20));  
	  System.out.println("Checking the entry for 70: ");
      System.out.println("Key(s): "+tree_map1.higherEntry(70));  
    }
}

Sample Output:

Orginal TreeMap content: {10=Red, 20=Green, 40=Black, 50=White, 60=Pink
}                                                                      
Checking the entry for 10:                                             
Key(s): 20=Green                                                       
Checking the entry for 20:                                             
Key(s): 40=Black                                                       
Checking the entry for 70:                                             
Key(s): null

For more Practice: Solve these Related Problems:

Write a Java program to use the higher() method on a TreeMap to get the least key strictly greater than a specified key.
Write a Java program to implement a method that returns the element immediately greater than a given key using higher().
Write a Java program to compare the result of higher() with a manual iteration over the sorted key set.
Write a Java program to handle null returns from higher() by providing a default value.

Java Code Editor:

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