Western Governors University (WGU) ICSC2100 C949 Data Structures and Algorithms I Practice Exam

In a hash table, the keys must indeed be unique. This uniqueness requirement is fundamental because a hash table uses keys to map to specific values via a hashing function. When a key is hashed, it generates an index where the associated value is stored. If two identical keys were allowed, the table would face ambiguity regarding which value to retrieve or store at the hashed index. This could lead to data integrity issues, such as overwriting existing values associated with the same key or failing to retrieve the correct value.

The uniqueness of keys ensures that each entry in the hash table can be accurately accessed without conflict. Therefore, in practice, when adding a key-value pair to the hash table, if the key already exists, an update or replacement should occur rather than duplicating the entry.

While other choices reflect different properties of data structures, they do not align with the requirements of a hash table regarding key storage. This highlights the importance of key uniqueness in maintaining the integrity and efficiency of data retrieval in hash tables.