Access map element (that does not exist)

---

• What happens when we access an element that does not exist?
• Go returns 0.
• So we can't know if the field exists and its value is 0 or if it does not exist at all.

examples/access-map-element/access_map_element.go

package main

import "fmt"

func main() {
    grades := make(map[string]int)

    grades["Mary"] = 99
    grades["Joe"] = 0
    fmt.Println(grades["Mary"])
    fmt.Println(grades["Joe"])
    fmt.Println(grades["Jane"])

}

99
0
0