SortedMap clear() method in Java with Examples

The clear() method in SortedMap Java is used to clear and remove all of the elements or mappings from a specified SortedMap collection.

Syntax:

void clear()

Parameters: The method does not accept any parameters.

Return Value: The method does not return any value.

Note: The clear() method in SortedMap is inherited from the Map interface in Java.

Below programs are used to illustrate the working of clear() Method:

Program 1: Mapping String Values to Integer Keys.

// Java code to illustrate the clear() method

import java.util.*;

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

        // Creating an empty SortedMap
        SortedMap<Integer, String> map
            = new TreeMap<Integer, String>();

        // Mapping string values to int keys
        map.put(10, "Geeks");
        map.put(15, "4");
        map.put(20, "Geeks");
        map.put(25, "Welcomes");
        map.put(30, "You");

        // Displaying the Map
        System.out.println(
            "Initial Mappings are: "
            + map);

        // Clearing the sorted map using clear()
        map.clear();

        // Displaying the final SortedMap
        System.out.println(
            "Finally the maps"
            + " look like this: "
            + map);
    }
}

Output:

Initial Mappings are:
 {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
Finally the maps look like this: {}

Program 2: Mapping Integer Values to String Keys.

// Java code to illustrate the clear() method

import java.util.*;

public class Map_Demo {
    public static void main(String[] args)
    {
        // Creating an empty SortedMap
        SortedMap<String, Integer> map
            = new TreeMap<String, Integer>();

        // Mapping int values to string keys
        map.put("Geeks", 10);
        map.put("4", 15);
        map.put("Geeks", 20);
        map.put("Welcomes", 25);
        map.put("You", 30);

        // Displaying the SortedMap
        System.out.println(
            "Initial Mappings are: "
            + map);

        // Clearing the SortedMap using clear()
        map.clear();

        // Displaying the final Map
        System.out.println(
            "Finally the maps "
            + "look like this: "
            + map);
    }
}

Output:

Initial Mappings are:
 {4=15, Geeks=20, Welcomes=25, You=30}
Finally the maps look like this: {}

Note: The same operation can be performed with any type of Mapping with variation and combination of different data types.

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#clear()