HashMap get() Method in Java
Last Updated :
11 Jan, 2023
The java.util.HashMap.get() method of HashMap 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:
Hash_Map.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.HashMap.get() method:
Program 1: Mapping String Values to Integer Keys.
import java.util.*;
public class Hash_Map_Demo {
public static void main(String[] args)
{
HashMap<Integer, String> hash_map = new HashMap<Integer, String>();
hash_map.put( 10 , "Geeks" );
hash_map.put( 15 , "4" );
hash_map.put( 20 , "Geeks" );
hash_map.put( 25 , "Welcomes" );
hash_map.put( 30 , "You" );
System.out.println( "Initial Mappings are: " + hash_map);
System.out.println( "The Value is: " + hash_map.get( 25 ));
System.out.println( "The Value is: " + hash_map.get( 10 ));
}
}
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Output:
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.
import java.util.*;
public class Hash_Map_Demo {
public static void main(String[] args)
{
HashMap<String, Integer> hash_map = new HashMap<String, Integer>();
hash_map.put( "Geeks" , 10 );
hash_map.put( "4" , 15 );
hash_map.put( "Geeks" , 20 );
hash_map.put( "Welcomes" , 25 );
hash_map.put( "You" , 30 );
System.out.println( "Initial Mappings are: " + hash_map);
System.out.println( "The Value is: " + hash_map.get( "Geeks" ));
System.out.println( "The Value is: " + hash_map.get( "You" ));
}
}
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Output:
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.
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