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[Golang reflect struct] #Go
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package main | |
import ( | |
"fmt" | |
"reflect" | |
"time" | |
) | |
func main() { | |
type T struct { | |
A int | |
B string | |
} | |
t := T{23, "skidoo"} | |
s := reflect.ValueOf(&t).Elem() | |
typeOfT := s.Type() | |
for i := 0; i < s.NumField(); i++ { | |
f := s.Field(i) | |
fmt.Printf("%d: %s %s = %v\n", i, typeOfT.Field(i).Name, f.Type(), f.Interface()) | |
} | |
{ | |
fmt.Println(time.Now().Format(time.RFC3339)) | |
t, _ := time.Parse(time.RFC3339, time.Now().Format(time.RFC3339)) | |
fmt.Println(t.Hour()) | |
} | |
} |
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package main | |
import ( | |
"fmt" | |
"reflect" | |
) | |
// Name of the struct tag used in examples | |
const tagName = "validate" | |
type User struct { | |
Id int `validate:"-"` | |
Name string `validate:"presence,min=2,max=32"` | |
Email string `validate:"email,required"` | |
} | |
func main() { | |
user := User{ | |
Id: 1, | |
Name: "John Doe", | |
Email: "john@example", | |
} | |
// TypeOf returns the reflection Type that represents the dynamic type of variable. | |
// If variable is a nil interface value, TypeOf returns nil. | |
t := reflect.TypeOf(user) | |
// Get the type and kind of our user variable | |
fmt.Println("Type:", t.Name()) | |
fmt.Println("Kind:", t.Kind()) | |
// Iterate over all available fields and read the tag value | |
for i := 0; i < t.NumField(); i++ { | |
// Get the field, returns https://golang.org/pkg/reflect/#StructField | |
field := t.Field(i) | |
// Get the field tag value | |
tag := field.Tag.Get(tagName) | |
fmt.Printf("%d. %v (%v), tag: '%v'\n", i+1, field.Name, field.Type.Name(), tag) | |
} | |
} |
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