java.util.IdentityHashMap.containsKey() Method


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Description

The containsKey(Object key) method is used to test whether the specified object reference is a key in this identity hash map.

Declaration

Following is the declaration for java.util.IdentityHashMap.containsKey() method.

public boolean containsKey(Object key)

Parameters

  • key -- This is the possible key to be checked.

Return Value

The method call returns 'true' if the specified object reference is a key in this map.

Exception

  • NA

Example

The following example shows the usage of java.util.IdentityHashMap.containsKey()

package com.tutorialspoint;

import java.util.*;

public class IdentityHashMapDemo {
   public static void main(String args[]) {
   // create identity hash map
   IdentityHashMap ihmap = new IdentityHashMap();
      
   // populate the map
   ihmap.put(1, "java");
   ihmap.put(2, "util");
   ihmap.put(3, "package");
      
   // check if key 3 exists
   boolean isavailable=ihmap.containsKey(3);

   System.out.println("Is key '3' exists: " + isavailable); 
   }    
}

Let us compile and run the above program, this will produce the following result.

Is key '3' exists: true

java_util_identityhashmap.htm

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