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.
// Java code to illustrate the get() method import java.util.*; public class Tree_Map_Demo { public static void main(String[] args) { // Creating an empty TreeMap TreeMap<Integer, String> tree_map = new TreeMap<Integer, String>(); // Mapping string values to int keys 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" ); // Displaying the TreeMap System.out.println( "Initial Mappings are: " + tree_map); // Getting the value of 25 System.out.println( "The Value is: " + tree_map.get( 25 )); // Getting the value of 10 System.out.println( "The Value is: " + tree_map.get( 10 )); } } |
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.
// Java code to illustrate the get() method import java.util.*; public class Tree_Map_Demo { public static void main(String[] args) { // Creating an empty TreeMap TreeMap<String, Integer> tree_map = new TreeMap<String, Integer>(); // Mapping int values to string keys 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 ); // Displaying the TreeMap System.out.println( "Initial Mappings are: " + tree_map); // Getting the value of "Geeks" System.out.println( "The Value is: " + tree_map.get( "Geeks" )); // Getting the value of "You" System.out.println( "The Value is: " + tree_map.get( "You" )); } } |
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.
Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.