java.util.IdentityHashMap.containsKey() Method

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