The java.util.TreeMap.get() method of TreeMap 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:
Tree_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.TreeMap.get() method:
Program 1: Mapping String Values to Integer Keys.
import java.util.*;
public class Tree_Map_Demo {
public static void main(String[] args)
{
TreeMap<Integer, String> tree_map = new TreeMap<Integer, String>();
tree_map.put( 10 , "Geeks" );
tree_map.put( 15 , "4" );
tree_map.put( 20 , "Geeks" );
tree_map.put( 25 , "Welcomes" );
tree_map.put( 30 , "You" );
System.out.println( "Initial Mappings are: " + tree_map);
System.out.println( "The Value is: " + tree_map.get( 25 ));
System.out.println( "The Value is: " + tree_map.get( 10 ));
}
}
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Output:
Initial Mappings are: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You}
The Value is: Welcomes
The Value is: Geeks
Program 2: Mapping Integer Values to String Keys.
import java.util.*;
public class Tree_Map_Demo {
public static void main(String[] args)
{
TreeMap<String, Integer> tree_map = new TreeMap<String, Integer>();
tree_map.put( "Geeks" , 10 );
tree_map.put( "4" , 15 );
tree_map.put( "Geeks" , 20 );
tree_map.put( "Welcomes" , 25 );
tree_map.put( "You" , 30 );
System.out.println( "Initial Mappings are: " + tree_map);
System.out.println( "The Value is: " + tree_map.get( "Geeks" ));
System.out.println( "The Value is: " + tree_map.get( "You" ));
}
}
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Output:
Initial Mappings are: {4=15, Geeks=20, Welcomes=25, You=30}
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.