Java TreeMap get() Method

The get() method of the TreeMap class in Java is used to retrieve or fetch the value mapped by a particular key mentioned in the parameter. If the key does not exist in the map, the method returns null.

Syntax of TreeMap get() Method

treeMap.get(Object key)

• Parameter: key: The method takes one parameter "key" of object type, and refers to the key whose associated value is supposed to be fetched. 
• Returns: The method returns the value associated with the "key" in the parameter, or null if no mapping exists for the key.

Examples of Java TreeMap get() Method

Example 1: In this example, we are going to create a TreeMap with integer keys and string values, and then we will fetch the values for specific keys using the get() method.

// Java program to demonstrate  // the get() method of TreeMap import java.util.*; public class Geeks {    public static void main(String[] args) {  // Create an empty TreeMap  TreeMap<Integer, String> tm = new TreeMap<Integer, String>();  // Map string values to int keys  tm.put(10, "Geeks");  tm.put(15, "4");  tm.put(20, "Geeks");  tm.put(25, "Welcomes");  tm.put(30, "You");  System.out.println("Initial mapping: " + tm);  // Get the value of key 25  System.out.println("The Value is: " + tm.get(25));  // Get the value of key 10  System.out.println("The Value is: " + tm.get(10));  } } 

Initial mapping: {10=Geeks, 15=4, 20=Geeks, 25=Welcomes, 30=You} The Value is: Welcomes The Value is: Geeks 

Example 2: In this example, we are going to create a TreeMap with string keys and integer values.

// Java program to demonstrate  // the get() method of TreeMap import java.util.*; public class Geeks {  public static void main(String[] args) {  // Create an empty TreeMap  TreeMap<String, Integer> tm = new TreeMap<String, Integer>();  // Map int values to string keys  tm.put("Geeks", 10);  tm.put("4", 15);  tm.put("Geeks", 20);   tm.put("Welcomes", 25);  tm.put("You", 30);  System.out.println("Initial Mapping: " + tm);  System.out.println("The Value is: " + tm.get("Geeks"));  System.out.println("The Value is: " + tm.get("You"));  } } 

Initial Mapping: {4=15, Geeks=20, Welcomes=25, You=30} The Value is: 20 The Value is: 30 

Important Points:

• If the key does not exist, get() method returns null.
• The duplicate keys will be overridden means only the latest value is retained.
• The treeMap stores keys in natural sorted order i.e. ascending for numbers, alphabetical for strings.
• The get() method can be used with any object types as long as the keys implement Comparable.