The clear() method of java.util.concurrent.ConcurrentSkipListMap is an in-built function in Java which removes all of the mappings from this map. This means that all the elements from the map are removed and an empty map is returned.
Syntax:
public void clear()
Parameter: The function does not accepts any parameters.
Return Value: The function removes all the mappings from this map.
Below programs illustrate the above method:
Program 1:
// Java Program Demonstrate clear()// method of ConcurrentSkipListMap  import java.util.concurrent.*;  class GFG {    public static void main(String[] args)    {          // Initializing the map        ConcurrentSkipListMap<Integer, Integer>            mpp = new ConcurrentSkipListMap<Integer,                                            Integer>();          // adding elements in map        for (int i = 1; i <= 5; i++)            mpp.put(i, i);          // print original map        System.out.println("map elements are: "                           + mpp);          mpp.clear();          // after clear() operation        System.out.println("after clear the map is: "                           + mpp);    }} |
Output:
map elements are: {1=1, 2=2, 3=3, 4=4, 5=5}
after clear the map is: {}
Program 2:
// Java Program Demonstrate clear()// method of ConcurrentSkipListMap  import java.util.concurrent.*;  class GFG {    public static void main(String[] args)    {          // Initializing the map        ConcurrentSkipListMap<Integer, Integer>            mpp = new ConcurrentSkipListMap<Integer,                                            Integer>();          // adding elements in map        for (int i = 1; i <= 10; i++)            mpp.put(i, i);          // print original map        System.out.println("map elements are: "                           + mpp);          mpp.clear();          // after clear() operation        System.out.println("after clear the map is: "                           + mpp);    }} |
Output:
map elements are: {1=1, 2=2, 3=3, 4=4, 5=5, 6=6, 7=7, 8=8, 9=9, 10=10}
after clear the map is: {}
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListMap.html#clear–
