Which of the following describes a characteristic of a TreeMap in Java?

Which of the following describes a characteristic of a TreeMap in Java?

• A. It allows null keys
• B. It maintains keys in a sorted order
• C. It offers faster average access time than HashMap
• D. It is synchronized by default

Answer: (B)

A TreeMap in Java is designed specifically to maintain its keys in a sorted order based on their natural ordering or by a specified comparator. This characteristic is crucial for scenarios where you need to ensure that the keys are stored in a predictable sequence, allowing for efficient range queries and ordered traversals. Additionally, the sorted nature of a TreeMap aligns with its underlying data structure, which is a Red-Black tree, a type of balanced binary search tree. This structure enables operations like insertion, deletion, and access to keys to be performed in logarithmic time, while also facilitating easy retrieval of entries in sorted order. In contrast, other map implementations, such as HashMap, do not maintain any order among their keys, and the order can appear random. Therefore, the ability of TreeMap to keep keys sorted is a defining feature that differentiates it from other map types in Java.

A TreeMap in Java is designed specifically to maintain its keys in a sorted order based on their natural ordering or by a specified comparator. This characteristic is crucial for scenarios where you need to ensure that the keys are stored in a predictable sequence, allowing for efficient range queries and ordered traversals.

Additionally, the sorted nature of a TreeMap aligns with its underlying data structure, which is a Red-Black tree, a type of balanced binary search tree. This structure enables operations like insertion, deletion, and access to keys to be performed in logarithmic time, while also facilitating easy retrieval of entries in sorted order.

In contrast, other map implementations, such as HashMap, do not maintain any order among their keys, and the order can appear random. Therefore, the ability of TreeMap to keep keys sorted is a defining feature that differentiates it from other map types in Java.