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() methodimport 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)); }} |
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.
// Java code to illustrate the get() methodimport 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")); }} |
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.
