In this shot, we will learn how to use the TreeMap.put() method in Java.
The TreeMap.put() method is present in the TreeMap class inside the java.util package.
TreeMap.put() is used to insert the key-value mappings in the TreeMap.
The syntax of the TreeMap.put() method is given below:
TreeMap.put(K key, V value);
The TreeMap.put() method accepts two parameters:
Key: The key which is to be inserted.Value: The value mapped with that key.The TreeMap.put() method can return one of the two values mentioned below:
NULL is returned.Let’s have a look at the code.
import java.util.*;class Main{public static void main(String[] args){TreeMap<Integer, String> t1 = new TreeMap<Integer, String>();t1.put(1, "Let's");t1.put(5, "see");t1.put(2, "TreeMap class");t1.put(27, "methods");t1.put(9, "in java.");System.out.println("Original TreeMap: " + t1);System.out.println(t1.put(27, "Hello"));System.out.println(t1.put(37, "Hello"));System.out.println("Modified TreeMap: " + t1);}}
In line 1, we import the required package.
In line 2, we made a Main class.
In line 4, we made a main() function.
In line 6, we declare a TreeMap consisting of keys of type Integer and values of type String.
From lines 8-12, we insert values in the TreeMap by using the TreeMap.put() method.
In line 14, we print the key-value pairs present in the TreeMap.
In lines 16-17, we insert two more key-value pairs. The first key, 27, is already present and gives the output as the previous value for this key. The second key, 37, is a new key and hence it gives the value as NULL in the output.
In line 19, we print the modified tree map.
So, this is how to use the TreeMap.put() method in Java.