How is an element added to a HashMap data structure?

HashMap in Java is a data structure that stores key-value pairs and provides fast access by key.

Adding an element to a HashMap occurs as follows:

1. The hash code of the key is computed using the hashCode() method.
2. Based on the hash code, the index of the bucket in the array is determined.
3. If the bucket is empty, a new entry with the key and value is created.
4. If there are already elements in the bucket (collision), a search is performed through the chain (linked list or tree) to check if the key already exists.
   • If the key is found, the value is updated.
   • If not, a new element is added to the chain.

Example of adding an element:

HashMap<String, Integer> map = new HashMap<>();
map.put("apple", 5); // adds a key-value pair "apple" and 5

Calling put initiates the process described above, ensuring data storage and quick access.