The get() method of Map interface in Java 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:
thisMap.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 this Map collection.
Below programs illustrates the working of java.util.Map.get() method:
Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the get() method import java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<Integer, String> map = new HashMap<Integer, String>(); // Mapping string values to int keys map.put( 10 , "Geeks" ); map.put( 15 , "4" ); map.put( 20 , "Geeks" ); map.put( 25 , "Welcomes" ); map.put( 30 , "You" ); // Displaying the Map System.out.println( "Initial Mappings are: " + map); // Getting the value of 25 System.out.println( "The Value is: " + map.get( 25 )); // Getting the value of 10 System.out.println( "The Value is: " + map.get( 10 )); } } |
Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4} The Value is: Welcomes The Value is: Geeks
Program 2: Mapping Integer Values to String Keys.
// Java code to illustrate the get() method import java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<String, Integer> map = new HashMap<String, Integer>(); // Mapping int values to string keys map.put( "Geeks" , 10 ); map.put( "4" , 15 ); map.put( "Geeks" , 20 ); map.put( "Welcomes" , 25 ); map.put( "You" , 30 ); // Displaying the Map System.out.println( "Initial Mappings are: " + map); // Getting the value of "Geeks" System.out.println( "The Value is: " + map.get( "Geeks" )); // Getting the value of "You" System.out.println( "The Value is: " + map.get( "You" )); } } |
Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25} 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.
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#get(java.lang.Object)
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