reflect.Pointer() Function in Golang with Examples

reflect.Pointer() Function in Golang with Examples

Last Updated : 05 May, 2020

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.Pointer() Function in Golang is used to get the v's value as a uintptr. To access this function, one needs to imports the reflect package in the program.

Syntax:
func (v Value) Pointer() uintptr
Parameters: This function does not accept any parameter. Return Value: This function returns the v's value as a uintptr.

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

C

// Golang program to illustrate
// reflect.Pointer() Function 
 
package main
 
import (
    "reflect"
    "unsafe"
    "fmt"
)
 
func main() {
    var s = struct{ foo int }{100}
    var i int
 
    rs := reflect.ValueOf(&s).Elem() 
    rf := rs.Field(0)              
    ri := reflect.ValueOf(&i).Elem()
     
    // use of Pointer() method
    rf = reflect.NewAt(rf.Type(), unsafe.Pointer(rf.UnsafeAddr())).Elem()
    ri.Set(rf)
    rf.Set(ri)
     
    fmt.Println(rf)
}

Output:

Example 2:

C

// Golang program to illustrate
// reflect.Pointer() Function 
 
package main
 
import (
    "fmt"
    "play.ground/foo"
    "reflect"
    "unsafe"
)
 
func GetUnexportedField(field reflect.Value) interface{} {
    return reflect.NewAt(field.Type(), unsafe.Pointer(field.UnsafeAddr())).Elem().Interface()
}
 
func SetUnexportedField(field reflect.Value, value interface{}) {
    reflect.NewAt(field.Type(), unsafe.Pointer(field.UnsafeAddr())).
        Elem().
        Set(reflect.ValueOf(value))
}
 
func main() {
    f := &foo.Foo{
        Exported: "Old Value ",
    }
 
    fmt.Println(f.Exported) 
     
    field := reflect.ValueOf(f).Elem().FieldByName("unexported")
    SetUnexportedField(field, "New Value")
    fmt.Println(GetUnexportedField(field))
}
 
-- go.mod --
module play.ground
 
-- foo/foo.go --
package foo
 
type Foo struct {
    Exported   string
    unexported string
}

Output:

Old Value 
New Value

reflect.Pointer() Function in Golang with Examples

S

SHUBHAMSINGH10

Improve

Article Tags :

Similar Reads

reflect.Int() 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.Int() Function in Golang is used to get the v's underlying value, as an int64. To access this function, one needs

reflect.PtrTo() 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.PtrTo() Function in Golang is used to get the pointer type with element t, i.e., t represents type Geek, PtrTo(t)

reflect.Index() 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.Index() Function in Golang is used to get the v's i'th element. To access this function, one needs to imports the

reflect.Interface() 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.Interface() Function in Golang is used to get the v's current value as an interface{}. To access this function, o

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 typ

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,

reflect.IsZero() 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.IsZero() Function in Golang is used to check whether v is the zero value for its type. To access this function, o

reflect.Kind() 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.Kind() Function in Golang is used to find the name of kind. To access this function, one needs to imports the ref

reflect.NewAt() 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.NewAt() Function in Golang is used to get the Value representing a pointer to a value of the specified type, usin

reflect.Indirect() 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.Indirect() Function in Golang is used to get the value that v points to, i.e., If v is a nil pointer, Indirect re