What is the underlying principle of the implementation of dictionaries in C#?

In C#, dictionaries are implemented using the hash table data structure. Hash table is a data structure that allows for quick storage and retrieval of key-value pairs by converting keys into a hash value and mapping that hash value to a storage bucket for fast lookup.

The dictionary uses an array as storage buckets, each bucket can store multiple key-value pairs. When storing a new key-value pair, the hash value of the key is calculated using a hash function. Then, the corresponding storage bucket is found based on the hash value, and the key-value pair is stored in that bucket.

When a key needs to be searched for, the hash function is used to calculate the hash value of the key and find the corresponding storage bucket based on the hash value. Then, the specified key is searched for in that storage bucket, and the corresponding value is returned.

In cases where multiple keys have the same hash value (known as hash collisions), dictionaries utilize data structures like linked lists or red-black trees to store these key-value pairs. This helps to maintain consistent search efficiency in scenarios where hash collisions occur frequently.

The underlying implementation of the dictionary also includes some other optimization techniques, such as dynamically adjusting the number of storage buckets and reallocating storage space, in order to improve the performance of the dictionary.