How to Create a TreeMap in Java and Add Key-Value Pairs in it?

In Java, a TreeMap maintains elements in a sorted order as it is an implementation of the SortedMap Interface. It stores key-value pairs in a sorted order. In this article, we will explore the creation of TreeMap in Java and learn the step-by-step process of adding key-value pairs.

Program to Create and Add Key-Value Pairs to a TreeMap in Java

Below is an example of how to create and after that how to add key-value pairs in a TreeMap.

1. Creating a TreeMap

TreeMap: {One=1, Three=3, Two=2}

Explanation of the Program:

• In the above program, tt imports the TreeMap class from the java.util package.
• It defines a class named TreeMapExample.
• Inside the main method:
  • It creates a TreeMap named numberMap with keys of type String and values of type Integer.
  • Key-value pairs are added to the numberMap.
  • The contents of the numberMap are displayed.

2. Adding Key-Value Pairs:

Fruit TreeMap: {Banana=Yellow, Kiwi=Green, Strawberry=Red}

Explanation of the Program:

• In the above program, it imports the TreeMap class from the java.util package.
• It defines a class named TreeMapExample.
• Inside the main method:
  • It creates a TreeMap named fruitMap with keys and values of type String.
  • Key-value pairs representing fruits and their colors are added to the fruitMap.
  • The contents of the fruitMap are displayed.z