How does inserting a value into a HashMap work?

When calling the put(key, value) method:

1. The hash of the key (key.hashCode()) is computed.
2. This hash is used to determine the index of the bucket in the array.
3. If the bucket is empty, a new Node entry with the key, value, hash, and a reference to the next value (which is null) is created and placed in the bucket.
4. If there are already entries in the bucket:
   • If an entry with the same key (key.equals(existingKey)) exists, the value in that entry is updated.
   • If the keys differ, the new entry is linked to existing entries in the form of a linked list or a tree (if the number of entries in the bucket exceeds a threshold, a transformation into a tree occurs to improve performance).
5. It checks whether the load factor * capacity threshold is exceeded. If so, the array size is doubled (resizing). All existing entries are redistributed across the new buckets.

// Example of calling the put method
hashMap.put("key", "value");