Java Data StructuresLesson 71Free preview

Java TreeMap

This lesson is part of Java · All levels

Summary

TreeMap stores keys and values in a balanced binary search tree so that keys are always in sequence. Its navigation features include firstKey(), lastKey(), and subMap makes it suitable for banded or range-based data. Just like TreeSet, the key to TreeMap must be Comparable or given a Comparator.

Key points

The keys are always sorted according to natural ordering or a Comparator
The main operation get, put, and remove is running
Provide firstKey(), lastKey(), higherKey(), lowerKey(), and subMap()
Do not allow the key to be used normally
The entrySet() iteration results in a key in ascending order

Full lesson

Code examples and quizzes

Full lessons, code examples, and quizzes are available to subscribers. 5 questions.