What is the underlying implementation principle of maps in Go language?

In the Go language, maps are implemented using hash tables at the underlying level.

A hash table is a data structure based on key-value pairs, allowing for fast insertion, deletion, and search operations by mapping keys to positions in the table.

In Go language, the underlying data structure of a map consists of a hash table and an array to store elements. When we create a map, Go language automatically allocates the underlying hash table and array for it.

The specific implementation process is as follows:

1. When a map is created in Go, the language allocates a hash table and an array with a specified size (defaulting to 0).
2. When we add elements to a map in Go, the language calculates the position (index) in the hash table based on the hash value of the key.
3. If the position is not already occupied, then store the element in that position.
4. If the position is already taken, conflicts will be resolved by using a linked list. This means that a new node will be added after the element at that position to store the new element.
5. When we search for an element in a map, Go language uses the hash value of the key to locate its position in the hash table. Then, it searches sequentially at that position through a linked list until it finds a matching key or the end of the list.

It is important to note that as the number of elements in the map increases, Go language automatically adjusts the size of the hash table to maintain its performance, reallocating more space when the load factor approaches a certain threshold.

In summary, in the Go language, maps are implemented using a hash table, which uses a hash function and linked lists to resolve conflicts, enabling fast insertion, deletion, and lookup operations.