Question

In a hash table, a special function, called a _____ , takes one data value and transforms the value (called the key) into an integer index that is used to retrieve the data. The index is then used to access the data record associated with the key.

1) Hash function
2) Index function
3) Transform function
4) Retrieve function

Answer 1

A hash function is the special function in a hash table that transforms a key into an integer index for data retrieval. This allows for efficient data access and storage within the hash table's array.

Step-by-step explanation:

In a hash table, a special function that takes one data value and transforms the value (called the key) into an integer index used to retrieve the data is called a hash function. The hash function is essential because it efficiently computes an index into an array in which the data value will be stored or searched. Using a good hash function can minimize the number of collisions—situations where different keys produce the same index—which would otherwise delay data retrieval due to additional steps needed to resolve the conflict.

To explain further, when the hash function receives a key, it processes it and returns a number that corresponds to a position within the hash table's array. The data associated with the key is then stored or looked up at this position. Therefore, the correct answer to the student's question is option 1) Hash Function.