reflect.New() 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.New() Function in Golang is used to get the Value representing a pointer to a new zero value for the specified type. To access this function, one needs to imports the reflect package in the program.

Syntax:

func New(typ Type) Value

Parameters: This function takes the following parameters:

  • typ : This parameter is the Type.

Return Value: This function returns a Value representing a pointer to a new zero value for the specified type.

Below examples illustrate the use of above method in Golang :
Example 1:



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// Golang program to illustrate
// reflect.New() Function 
   
package main
   
import (
    "fmt"
    "reflect"
)
   
// Main function 
func main() {
    t := reflect.TypeOf(5)
       
    //use of ArrayOf method
    arr := reflect.ArrayOf(4, t)
    inst := reflect.New(arr).Interface().(*[4]int)
   
    for i := 1; i <= 4; i++ {
        inst[i-1] = i*i
    }
   
    fmt.Println(inst)
}

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Output:

&[1 4 9 16]

Example 2:

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// Golang program to illustrate
// reflect.New() Function 
   
package main
   
import (
    "fmt"
    "reflect"
)
    
type Geek struct {
    A int `tag1:"First Tag" tag2:"Second Tag"`
    B string
}
  
// Main function
func main() {
    greeting := "GeeksforGeeks"
    f := Geek{A: 10, B: "Number"}
  
    gVal := reflect.ValueOf(greeting)
  
    fmt.Println(gVal.Interface())
  
    gpVal := reflect.ValueOf(&greeting)
    gpVal.Elem().SetString("Articles")
    fmt.Println(greeting)
  
    fType := reflect.TypeOf(f)
    fVal := reflect.New(fType)
    fVal.Elem().Field(0).SetInt(20)
    fVal.Elem().Field(1).SetString("Number")
    f2 := fVal.Elem().Interface().(Geek)
    fmt.Printf("%+v, %d, %s\n", f2, f2.A, f2.B)
}

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Output:

GeeksforGeeks
Articles
{A:20 B:Number}, 20, Number



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