It can be as challenging to understand when and how to use a Java TreeMap as it is to navigate a dense forest, with each turn revealing something new.
But as with any worthwhile endeavour, having the correct tools on hand makes everything simpler; and with TreeMap in Java, you’ll have exactly what you need to navigate around.
We’ll examine what a Java TreeMap is in this article and go over its benefits over other data structures. We’ll also look at illustrations of its application in actual-world situations. Check out our free Java course with certificate to learn more about TreeMap in Java, how it works, and how it is related to HashMap and LinkedHashMap.
What is TreeMap in Java?
A data structure for storing and organising things according to key-value pairs is called a Java TreeMap. It offers rapid ways to seek particular elements and effective ways to discover what keys are connected to an element. It is comparable to a hash map, except it also preserves the order in which the objects were inserted.
TreeMap is an implementation of NavigableMap based on Red-Black trees. It is arranged in the order that its keys naturally appear. Similar to the HashMap class, the TreeMap class implements the Map interface. The primary distinction between both is that TreeMap is sorted in the ascending order of its keys, whereas HashMap is an unordered collection. Because TreeMap is an unsynchronized collection type, thread-safe operations cannot be performed on it until and unless synchronised explicitly
A TreeMap’s root node is made up of sub-nodes (map components) that can either be keys or values. Each node in the tree contains a parent and a child, indicating that it is hierarchical. This makes it simple to quickly and simply access various areas of the map.
Advantages of Using Java TreeMaps
Compared to more traditional data structures like HashMaps, Arrays, and Linked Lists, Java TreeMaps provides a few advantages. They can hold an infinite amount of key-value pairs without degrading performance, for starters. Because they are not required to retain pointers to other objects, they consume less memory than conventional data structures.
Java TreeMaps are also incredibly easy to search through, which makes them perfect for applications that need quick access. They also provide a simple method for grouping components based on their keys, values, or both. As a result, information pertaining to a specific key or value can be rapidly found.
When should you use Java TreeMaps?
Java TreeMaps are useful for many different activities. Here are a few typical instances:
- Keeping coordinates for locations to be plotted on a map: Java’s built-in tree structure makes it simple to store and access location information like latitude and longitude.
- Genre-based categorization of music files: TreeMaps make it simple to store and arrange music files so that users can quickly locate what they’re looking for.
- Making complex databases searchable: Java TreeMaps can make databases that are simple to query and browse through.
Java TreeMap Examples
- Creating a Java TreeMap
We can make a new TreeMap object in this example and add two entries. The map is then printed out to show what is on it.
- Retrieving an Entry from a Java TreeMap
In this case, we may receive the value linked to a certain key using the get() method. In this instance, the output will be “value1”.
- Iterating Through the Java TreeMap
To print out all the keys on the map in this example, we may go over them all using the for-each loop.
- Default Sorting
Additionally, you can group elements into categories and order them based on their keys or values. The components are organised alphabetically by their keys.
- Custom Sorting
Custom sorting is another option. In this example, a custom Comparator object is used to order the items according to their values.
Which map should you use (HashMap, LinkedHashMap, or TreeMap?
Your specific use case and the kinds of procedures you require will determine the answer to this inquiry. Use HashMap for quick lookups if you require them. Use LinkedHashMap if you need an insertion order or access order. Use TreeMap to sort keys.
Data storage, organisation, and retrieval can be made simple with Java TreeMaps, a fantastic tool. You may build intricate databases using TreeMaps that are simple to query and search through. Additionally, you can build custom sorting or use default sorting based on your requirements.
Conclusion If you want to learn how TreeMap works in Java, you should check out our Java online tutorial.
