Can you give an example of when and why data hashing is used?

Data hashing is used for fast searching, comparison, and integrity verification of data.

Examples of use:

• In collections such as HashMap or HashSet, for quick access to elements by key.
• To verify the integrity of files or messages (e.g., checksums).
• In authentication and password storage (password hashing).

Example in Java using HashMap:

import java.util.HashMap;

public class Example {
    public static void main(String[] args) {
        HashMap<String, Integer> map = new HashMap<>();
        map.put("apple", 3);
        map.put("banana", 5);

        System.out.println(map.get("apple")); // Fast access to value by key
    }
}

Here, the hash function is used inside HashMap for quick determination of the element's position.