golang的New研究

直接上代码：

package main

import (
	"fmt"
	"reflect"
)

func main() {
	var n = 33
	var pn  = &n
	var ppn = &pn

	// new可以定义不同类型的地址，可以是int/int*/int**，都是可以的，对应的值也是需要正确的

	{
		nNew := reflect.New(reflect.TypeOf(n))
		nNew.Elem().Set(reflect.ValueOf(n))
		//pnew.Elem().Set(reflect.ValueOf(pn))// reflect.Set: value of type *int is not assignable to type int
		//pnew.Elem().Set(reflect.ValueOf(ppn)) // reflect.Set: value of type **int is not assignable to type int
		fmt.Println(nNew)
	}

	{
		pnNew := reflect.New(reflect.TypeOf(pn))
		//pnew.Elem().Set(reflect.ValueOf(n)) // reflect.Set: value of type int is not assignable to type *int
		pnNew.Elem().Set(reflect.ValueOf(pn))
		{
			nNew := reflect.New(reflect.TypeOf(n))
			nNew.Elem().Set(reflect.ValueOf(n))
			pnNew.Elem().Set(nNew)
		}
		//pnew.Elem().Set(reflect.ValueOf(ppn)) // reflect.Set: value of type **int is not assignable to type *int
		fmt.Println(pnNew)
	}


	{
		types := reflect.TypeOf(ppn).String()
		fmt.Println(types)
		ppnNew := reflect.New(reflect.TypeOf(ppn))
		//pnew.Elem().Set(reflect.ValueOf(n)) // reflect.Set: value of type int is not assignable to type **int
		// pnew.Elem().Set(reflect.ValueOf(pn)) // reflect.Set: value of type *int is not assignable to type **int
		ppnNew.Elem().Set(reflect.ValueOf(ppn))
		{
			pnNew := reflect.New(reflect.TypeOf(pn))
			{
				nNew := reflect.New(reflect.TypeOf(n))
				nNew.Elem().Set(reflect.ValueOf(n))
				pnNew.Elem().Set(nNew)
			}
			ppnNew.Elem().Set(pnNew)
		}
		fmt.Println(ppnNew)
	}
}

 

 

reflect.New()后面的类型可以是int/int*/int**, 也就是可以是对象/指针/指针的指针

然后设置值的时候需要一一对应上