What is AbstractMap clear() in Java?

AbstractMap.clear() is a method of the Java AbstractMap class. We use it to remove all of the mappings from an AbstractMap. The AbstractMap will become empty after we call this method.

Syntax

AbstractMap.clear()

The AbstractMap.clear() takes no parameter and doesn’t return any valuei.e., void.

The method throws an UnsupportedOperationException error if the AbstractMap does not support the clear() operation.

AbstractMapDemo.java illustration
AbstractMapDemo.java illustration

Code

We can see what’s illustrated above in the code below.

import java.util.*;
class AbstractMapDemo {
public static void main(String[] args)
{
// Creating an AbstractMap
AbstractMap<Integer, String>
abstractMap = new HashMap<Integer, String>();
// Mapping string values to int keys
abstractMap.put(21, "Shot");
abstractMap.put(42, "Java");
abstractMap.put(34, "Yaaaayy");
// Printing the AbstractMap
System.out.println("The Mappings are: "
+ abstractMap);
// Clearing the AbstractMap using clear() method
abstractMap.clear();
// Printing the final AbstractMap
System.out.println("The Final Mappings are: "
+ abstractMap);
}
}

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