package main

import (
    "fmt"
    "reflect"
)

// 1. reflect 获取变量的类型、值
func reflectFn(x interface{}) {
    v := reflect.TypeOf(x)
    v1 := reflect.ValueOf(x)
    fmt.Println(v, v1, v.Name(), v.Kind())
}

func f1() {
    type myInt int
    type Person struct {
        Name string
        Age  int
    }
    var x myInt = 34
    var p = Person{
        Name: "张三",
        Age:  20,
    }
    y := "hello"
    arr := [3]int{1, 2, 3}
    sli := []int{4, 5, 6}

    reflectFn(3)        // int 3 int int
    reflectFn(3.14)     // float64 3.14 float64 float64
    reflectFn(true)     // bool true bool bool
    reflectFn("golang") // string golang string string
    reflectFn(x)        // main.myInt 34 myInt int
    reflectFn(p)        // main.Person {张三 20} Person struct
    reflectFn(&y)       // *string 0xc000046230         ptr
    reflectFn(arr)      // [3]int [1 2 3]               array
    reflectFn(sli)      // []int [4 5 6]                slice
}

// 2. reflect 修改变量的值
func reflectFn1(x interface{}) {
    v := reflect.ValueOf(x)
    if v.Elem().Kind() == reflect.String {
        v.Elem().SetString("world")
    }
}

func f2() {
    x := "hello"
    reflectFn1(&x)
    fmt.Println("修改后:", x) // 修改后: world
}

func main() {
    f2()
}