T常用的格式化字符串有：

%v the value in a default format
when printing structs,the plus flag (%+v) adds field names
%#v a Go-Syntax representation of the value
%T a Go-Syntax representation of the type of the value

不同类型默认的%v 如下:

bool: %t
int,int8 etc.: %d
uint,uint8 etc.: %d,%#x if printed with %#v
float32,complex64,etc: %g
string: %s
chan: %p
pointer: %p

对于interface{},%v会打印实际类型的值。
举例说明如下。

example

package main
 
import (
 
        "fmt"
)
 
 
type Power struct{
        age int
        high int
        name string
}
 
func main() {
 
        var i Power = Power{age: 10,high: 178,name: "NewMan"}
 
        fmt.Printf("type:%T\n",i)
        fmt.Printf("value:%v\n",i)
        fmt.Printf("value+:%+v\n",i)
        fmt.Printf("value#:%#v\n",i)
 
 
        fmt.Println("========interface========")
        var interf interface{} = i
        fmt.Printf("%v\n",interf)
        fmt.Println(interf)
}

output:

type:main.Power value:{10 178 NewMan} value+:{age:10 high:178 name:NewMan} value#:main.Power{age:10,high:178,name:”NewMan”} ========interface======== {10 178 NewMan} {10 178 NewMan}