In Go, we can check if a hash (also called a map) includes a specific key using the map[key] syntax. This returns two values: the value associated with the key, and a boolean flag indicating whether the key exists in the map.
Here's an example:
package main
import "fmt"
func main() {
// create a map with string keys and int values
scores := map[string]int{
"Alice": 15,
"Bob": 23,
"Carl": 42,
}
// check if the map contains a key
if score, ok := scores["Bob"]; ok {
fmt.Printf("Bob's score is %d\n", score)
} else {
fmt.Println("Bob's score is not available")
}
// check if the map contains a key that doesn't exist
if score, ok := scores["Dave"]; ok {
fmt.Printf("Dave's score is %d\n", score)
} else {
fmt.Println("Dave's score is not available")
}
}
In this example, we create a map called scores with string keys and int values. We then check if the map contains the key "Bob" using the scores["Bob"] syntax. Since "Bob" exists in the map, we print his score of 23.
We also check for the key "Dave", which doesn't exist in the map. In this case, the boolean flag ok is set to false, and we print an error message indicating that Dave's score is not available.