How to use reflect in Golang?

In Golang, the reflect package provides a mechanism to inspect the type and value of variables, as well as the ability to dynamically call methods and modify values at runtime. Here are some common examples of operations using reflect:

1. Get the type of variable.

package main

import (
	"fmt"
	"reflect"
)

func main() {
	var x = 42
	fmt.Println(reflect.TypeOf(x))  // 输出：int
}

1. Get the value of the variable.

package main

import (
	"fmt"
	"reflect"
)

func main() {
	var x = 42
	value := reflect.ValueOf(x)
	fmt.Println(value.Int())  // 输出：42
}

1. Change the value of the variable.

package main

import (
	"fmt"
	"reflect"
)

func main() {
	var x = 42
	value := reflect.ValueOf(&x).Elem()  // 取变量的地址并获取可修改的值
	value.SetInt(24)
	fmt.Println(x)  // 输出：24
}

1. Method invocation:

package main

import (
	"fmt"
	"reflect"
)

type Person struct {
	Name string
	Age  int
}

func (p Person) SayHello() {
	fmt.Println("Hello, my name is", p.Name)
}

func main() {
	p := Person{Name: "Alice", Age: 20}
	value := reflect.ValueOf(p)
	method := value.MethodByName("SayHello")
	method.Call(nil)  // 输出：Hello, my name is Alice
}

These are just some basic examples of how to use reflection, the reflect package provides more functionality for handling reflection operations on variables. Please be cautious when using reflection as it can lead to a decrease in performance.