The clear() method of Java AbstractCollection in Java is used to remove all of the elements from the Collection. Using the clear() method only clears all the element from the collection and does not delete the collection. In other words, it can be said that the clear() method is used to only empty an existing AbstractCollection.
Syntax:
AbstractCollection.clear()
Return Value: The function does not return any value.
Below programs illustrate the AbstractCollection.clear() method:
Program 1:
// Java code to illustrate clear(Object o)// of AbstractCollelction  import java.util.*;import java.util.AbstractCollection;  public class AbstractCollectionDemo {    public static void main(String[] args)    {          // Create an empty Collection        AbstractCollection<Object>            abs = new ArrayList<Object>();          // Use add() method to add        // elements in the collection        abs.add("Welcome");        abs.add("To");        abs.add("Geeks");        abs.add("4");        abs.add("Geeks");          // Displaying the Collection        System.out.println("AbstractCollection: "                           + abs);          // Clearing the Collection        abs.clear();          // Displaying the Collection        System.out.println("AbstractCollection "                           + "after using clear: "                           + abs);    }} |
Output:
AbstractCollection: [Welcome, To, Geeks, 4, Geeks] AbstractCollection after using clear: []
Program 2:
// Java code to illustrate clear(Object o)// of AbstractCollelction  import java.util.*;import java.util.AbstractCollection;  public class AbstractCollectionDemo {    public static void main(String[] args)    {          // Create an empty collection        AbstractCollection<Object>            abs = new LinkedList<Object>();          // Use add() method to add        // elements in the collection        abs.add(15);        abs.add(20);        abs.add(25);        abs.add(30);        abs.add(35);          // Displaying the Collection        System.out.println("AbstractCollection: "                           + abs);          // Clearing the Collection        abs.clear();          // Displaying the Collection        System.out.println("AbstractCollection "                           + "after using clear: "                           + abs);    }} |
Output:
AbstractCollection: [15, 20, 25, 30, 35] AbstractCollection after using clear: []
