Go Language: Map: Check whether an item exists in map or not

By using double value context, we can check whether an item exists in the map or not.

value1, ok := employees[1]

if !ok {

         fmt.Println("Value not found for key 1")

} else {

         fmt.Println("Value for key 1 : ", value1)

}

ok value will be assigned to true, if the key is inside the map, else false.

value1 is assigned with the value of key 1, if key 1 exists in the map else assigned with zero value.

App.go

package main

import "fmt"

func main() {

 employees := map[int]string{
  1: "Krishna",
  2: "Ram", //Must have trailing comma
 }

 value1, ok := employees[1]
 if !ok {
  fmt.Println("Value not found for key 1")
 } else {
  fmt.Println("Value for key 1 : ", value1)
 }

 value2, ok := employees[10]
 if !ok {
  fmt.Println("Value not found for key 10")
 } else {
  fmt.Println("Value for key 10 : ", value2)
 }
}

Output

Value for key 1 :  Krishna

Value not found for key 10

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