The java.util.WeakHashMap.get() method of WeakHashMap class is used to retrieve or fetch the value mapped by a particular key mentioned in the parameter. It returns NULL when the map contains no such mapping for the key.
Syntax:
WeakHashMap.get(Object key_element)
Parameter: The method takes one parameter key_element of object type and refers to the key whose associated value is supposed to be fetched.
Return Value: The method returns the value associated with the key_element in the parameter.
Below programs illustrates the working of java.util.WeakHashMap.get() method:
Program 1:
// Java code to illustrate the get() method import java.util.*;
public class Weak_Hash_Map_Demo {
public static void main(String[] args)
{
// Creating an empty WeakHashMap
Map<Integer, String> weak_hash = new WeakHashMap<Integer, String>();
// Mapping string values to int keys
weak_hash.put( 10 , "Geeks" );
weak_hash.put( 15 , "4" );
weak_hash.put( 20 , "Geeks" );
weak_hash.put( 25 , "Welcomes" );
weak_hash.put( 30 , "You" );
// Displaying the WeakHashMap
System.out.println( "Initial Mappings are: " + weak_hash);
// Getting the value of 25
System.out.println( "The Value is: " + weak_hash.get( 25 ));
// Getting the value of 10
System.out.println( "The Value is: " + weak_hash.get( 10 ));
}
} |
Initial Mappings are: {30=You, 15=4, 10=Geeks, 25=Welcomes, 20=Geeks} The Value is: Welcomes The Value is: Geeks
Program 2:
// Java code to illustrate the get() method import java.util.*;
public class Weak_Hash_Map_Demo {
public static void main(String[] args)
{
// Creating an empty WeakHashMap
Map<String, Integer> weak_hash = new WeakHashMap<String, Integer>();
// Mapping int values to string keys
weak_hash.put( "Geeks" , 10 );
weak_hash.put( "4" , 15 );
weak_hash.put( "Geeks" , 20 );
weak_hash.put( "Welcomes" , 25 );
weak_hash.put( "You" , 30 );
// Displaying the WeakHashMap
System.out.println( "Initial Mappings are: " + weak_hash);
// Getting the value of "Geeks"
System.out.println( "The Value is: " + weak_hash.get( "Geeks" ));
// Getting the value of "You"
System.out.println( "The Value is: " + weak_hash.get( "You" ));
}
} |
Initial Mappings are: {Welcomes=25, 4=15, You=30, Geeks=20} The Value is: 20 The Value is: 30
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.