Questions tagged [reflect]
123 questions
-1
votes
1 answer
Explain the printed values of method expressions
The following code tries to show the address of a method associated to struct.
package main
import (
"fmt"
"reflect"
)
type II interface {
Callme()
}
type Str struct {
I int
S string
}
func (s *Str) Callme () {
…
river
- 694
- 6
- 22
-1
votes
1 answer
IOS swift get a class by a string
I create two view. 1. ViewController by storyboard 2. A UIView by new a class. I want to use UIView class name: "ViewOne" to convert to a class, then load this UIView into the ViewController.
viewcontroller code:
override func viewDidLoad() {
…
A.Sheh
- 61
- 8
-2
votes
3 answers
how to use reflect know the slice data type?
i want to fill the slice data , but using reflect.kind() only let me know field(0) is slice ,
but i don't know it is which type of slice , it culd be int[] or string[] or other type slice
befor i know what slice data type , hastily set value will…
AM031447
- 475
- 1
- 8
- 21
-2
votes
1 answer
When type is []byte, it fails at case statement in golang
func Test(val any) {
switch reflect.TypeOf(val) {
case nil://ok
case string://ok
case []byte://error here,expected expression
}
}
As the code above, I am trying to make some statement according to the type of input value.…
tanxin
- 145
- 10
-2
votes
1 answer
Extract value from an array in a Json
I'm trying to get "boots" value
My func main
varjson:=`{
"identifier": "1",
"name": "dumbname",
"person": {
"items": null,
"inventory": [
{
"T-shirt": "black",
"Backpack": {
"BigPocket": {
…
NexDanger
- 43
- 11
-2
votes
1 answer
Set interface values returned by interface method with reflect
Given an interface that returns a slice of pointer types but wrapped as an interface type. Is it possible to modify the values?
type Base interface {
Do()
}
type Meta interface {
Base
Children() []Base
}
type A struct {
}
func (a *A)…
Mahoni
- 7,088
- 17
- 58
- 115
-2
votes
1 answer
Is it possible to add a key-value pair to a map of unknown type in Go?
I have multiple JSON files with different formats. All of them consist of an array which contain maps. The maps, however, have different structures.
a.json
[
{
"a": "b",
"c": ["d", "e"]
}
]
b.json
[
{
"f": ["g",…
David Bryant
- 29
- 4
-2
votes
1 answer
Cast an interface using a pointer of a Slice to iterate its values
Context:
Using a custom Binder and Validator in Echo Framework. The binder use a signature of (interface{}, echo.Context), but a pointer is always passed and checked by echo.DefaultBinder.
I'm having trouble validating an array of struct for some…
Alex Boutin
- 157
- 1
- 8
-2
votes
1 answer
Loop through the Nth fields one time of struct n a Go
Iterate through the fields of a struct in Go
I have read above thread and now I'm trying to extend it by processing multiple items at a time
package main
import (
"fmt"
"reflect"
)
type BaseStats struct {
value1 int
value2 …
GarfieldCat
- 389
- 4
- 12
-2
votes
2 answers
Print the key/value types of a Golang map
I am trying to print the type of a map, eg: map[int]string
func handleMap(m reflect.Value) string {
keys := m.MapKeys()
n := len(keys)
keyType := reflect.ValueOf(keys).Type().Elem().String()
valType := m.Type().Elem().String()
…
user12849275
-2
votes
1 answer
Is there a way to handle generic function in go
I am new to go, and wanted to implement a scheduler that will recieve tasks(i.e interval + handler).
I got stuck in the part where I should get the handlers as go is a static language(I can't get a generic function signature).
I came up with the…
Gal Rotenberg
- 43
- 7
-2
votes
1 answer
`reflect.Kind()` of Slice Becomes `Struct` When Stored Inside Pointer
When checking the reflect.Kind() of a slice, reflect correctly identifies it as a slice when not stored inside a pointer:
package main
import (
"fmt"
"reflect"
)
type Dog struct {
Name string
Age int
}
func main() {
var dogs…
Floating Sunfish
- 4,920
- 5
- 29
- 48
-2
votes
1 answer
How to specify the field we wanna use from a struct?
I have a struct composed of multiple fields of same type.
type test struct{
A int
B int
C int
}
I want to apply a function that does the same things to the three fields, but I only wanna do it on one each time.
function…
Dylan
- 197
- 1
- 2
- 10
-3
votes
1 answer
In this case why do i need to convert the value type to interface{} when the receiving parameter of the function is already interface?
table := s.Model(reflect.New(destType).Elem().Interface()).RefTable()
func (s *Session) Model(dest interface{}) *Session {
log.Info(reflect.TypeOf(dest))
if s.refTable == nil || s.refTable != dest {
s.refTable = schema.Parse(dest,…
Pablo
- 5
- 1
-3
votes
3 answers
Why is "int" convertible to "string"?
This example shows that int type is convertible to string type. But my question is why?
package main
import (
"fmt"
"reflect"
)
func main() {
it := reflect.TypeOf(42)
st := reflect.TypeOf("hello")
fmt.Printf("%q is convertible…
riad
- 23
- 1
- 5