reflect.TypeOf() 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.TypeOf() Function in Golang is used to get the reflection Type that represents the dynamic type of i. To access this function, one needs to imports the reflect package in the program.

Syntax:

func TypeOf(i interface{}) Type

Parameters: This function takes only one parameters of interface( i ).

Return Value: This function returns the reflection Type.

Below examples illustrate the use of above method in Golang:

Example 1:

// Golang program to illustrate
// reflect.TypeOf() Function

package main

import (
    "fmt"
    "reflect"
)

// Main function
func main() {

    tst1 := "string"
    tst2 := 10
    tst3 := 1.2
    tst4 := true
    tst5 := []string{"foo", "bar", "baz"}
    tst6 := map[string]int{"apple": 23, "tomato": 13}


    // use of TypeOf method
    fmt.Println(reflect.TypeOf(tst1))
    fmt.Println(reflect.TypeOf(tst2))
    fmt.Println(reflect.TypeOf(tst3))
    fmt.Println(reflect.TypeOf(tst4))
    fmt.Println(reflect.TypeOf(tst5))
    fmt.Println(reflect.TypeOf(tst6))

}

Output:

string
int
float64
bool
[]string
map[string]int

Example 2:

// Golang program to illustrate
// reflect.TypeOf() Function

package main

import (
    "fmt"
    "io"
    "os"
    "reflect"
)

// Main function
func main() {

    // use of TypeOf method
    tt := reflect.TypeOf((*io.Writer)(nil)).Elem()

    fileType := reflect.TypeOf((*os.File)(nil))
    fmt.Println(fileType.Implements(tt))

}

Output:

true