What is a map in Go, how is it structured internally, what is a collision, and how is it handled?

In Go, a map is a built-in data type for storing key-value pairs with fast access. Inside, a map implements a hash table mechanism.

Internal structure:

• The key is hashed into an integer value.
• The hash determines the index of the bucket where pairs are stored.
• Each bucket contains multiple key-value pairs.

Collision — a situation where different keys have the same hash and fall into the same bucket. To handle this, Go uses:

• Storing multiple pairs in one bucket.
• When there are many collisions, rehashing occurs with an increase in the number of buckets.

This allows maintaining quick access to elements even during collisions.

Example of using a map:

m := make(map[string]int)
"apple" := 5
fmt.Println(m["apple"]) // 5

Thus, a map in Go is an efficient structure for an associative array with internal optimization to minimize the impact of collisions.