reflect.MapIndex() Function in Golang with Examples
Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.MapIndex() Function in Golang is used to get the value associated with key in the map v. To access this function, one needs to imports the reflect package in the program.
Syntax:
func (v Value) MapIndex(key Value) ValueParameters: This function does not accept any parameter.
Return Value: This function returns the value associated with key in the map v.
Below examples illustrate the use of the above method in Golang:
Example 1:
// Golang program to illustrate // reflect.MapIndex() Function package main import ( "fmt" "reflect" ) func main() { test := map[string]interface{}{ "First" : "firstValue" } Pass(test) } // Main function func Pass(d interface{}) { mydata := reflect.ValueOf(d).MapIndex(reflect.ValueOf( "First" )) fmt.Printf( "Value: %+v \n" , mydata.Interface()) fmt.Printf( "Kind: %+v \n" , mydata.Kind()) fmt.Printf( "Kind2: %+v \n" , reflect.ValueOf(mydata.Interface()).Kind()) } |
Output:
Value: firstValue Kind: interface Kind2: string
Example 2:
// Golang program to illustrate // reflect.MapIndex() Function package main import ( "fmt" "reflect" ) type Test struct { Data string } func (t Test) GetData() string { return t.Data } type Stringer interface { GetData() string } // Main function func main() { d := map[string]Stringer{ "Beginner" : Test{Data: "Null" }} mydata := reflect.ValueOf(d).MapIndex(reflect.ValueOf( "Beginner" )) fmt.Println(reflect.ValueOf(mydata.Interface())) } |
Output:
{Null}