WeakHashMap get() Method in Java
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() methodimport 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)); }} |
Output:
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() methodimport 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")); }} |
Output:
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.
