What is the SortedMap.tailMap() method in Java?

Overview

In this shot, we will discuss how to use the SortedMap.tailMap() method in Java. This method is present in the SortedMap interface inside the java.util package.

The SortedMap.tailMap() method obtains the part of the map whose keys are greater than or equal to a given SortedMap key.

Syntax

SortedMap.tailMap(key)

Parameter

The SortedMap.tailMap() method takes one parameter:

  • Key: This method accepts a key of SortedMap.

Return value

The SortedMap.tailMap() method returns:

  • Map: The part of the map whose keys are greater than or equal to the given key of SortedMap.

Code

Let’s look at the code snippet below:

import java.util.*;
class Main 
{
    public static void main(String[] args)
    {
        SortedMap<Integer, String> s = new TreeMap<Integer,String>();
        s.put(2,"Welcome");
        s.put(12,"to");
        s.put(31,"the");
        s.put(18,"world");
        s.put(25,"of");
        s.put(36,"java");
        System.out.println("SortedMap mappings are: "+ s);
        System.out.println("Map from the key=25: " + s.tailMap(25));
    }
}

Explanation

  • In line 1, we import the required package.
  • In line 2, we make a Main class.
  • In line 4, we make a main function.
  • In line 6, we declare a SortedMap consisting of Integer type keys and String type values.
  • From lines 8-13, we insert values in the SortedMap.
  • In line 15, we display the values of the SortedMap.
  • In line 17, we will call the SortedMap.tailMap() method to obtain and display the returned map. The returned map will contain (key,value) pairs of keys equal to or greater than the key passed to the SortedMap.

In this way, we can use the SortedMap.tailMap() method in Java.

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