go - 为什么 fmt.Printf() 会在内存地址等其他包中记录 `const`？

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fmt.Printf() 是怎么做到的？对待 %x?当参数为 var 时或 const .我从书上读到 const没有Type在指定之前，很难理解。

const AValue int32 = 1049088

func main() {
    fmt.Printf("%#x\n", 1049088)
    fmt.Printf("%#x\n", AValue)

    fmt.Printf("%#x\n", int(time.Friday))
    fmt.Printf("%#x\n", time.Friday)
}

日志:0x100200 // 10490880x100200 // AValue0x5 // int(time.Friday)0x467269646179 // time.Friday is a type Weekday int

Is `0x467269646179` some kind address of time.Friday?

Answer 1

来自 docs :

Except when printed using the verbs %T and %p, special formatting considerations apply for operands that implement certain interfaces. In order of application:
...
5. If an operand implements method String() string, that method will be invoked to convert the object to a string, which will then be formatted as required by the verb (if any).

对于 string动词格式定义为:

%s  the uninterpreted bytes of the string or slice
%q  a double-quoted string safely escaped with Go syntax
%x  base 16, lower-case, two characters per byte
%X  base 16, upper-case, two characters per byte

所以0x467269646179是 base 16, lower-case, two characters per byte time.Friday.String() 的输出.
https://play.golang.org/p/avV-X2uiL1D