如何在Golang中将符文转换为unicode样式的字符串，例如`\ u554a`？

If you run fmt.Println("\u554a"), it shows '啊'.

But how to get unicode-style-string \u554a from a rune '啊' ?

IMHO, it should be better:

func RuneToAscii(r rune) string {
    if r < 128 {
        return string(r)
    } else {
        return "\\u" + strconv.FormatInt(int64(r), 16)
    }
}

For example,

package main

import "fmt"

func main() {
    r := rune('啊')
    u := fmt.Sprintf("%U", r)
    fmt.Println(string(r), u)
}

Output:

啊 U+554A

package main

import "fmt"
import "strconv"

func main() {
    quoted := strconv.QuoteRuneToASCII('啊') // quoted = "'\u554a'"
    unquoted := quoted[1:len(quoted)-1]      // unquoted = "\u554a"
    fmt.Println(unquoted)
}

This outputs:

\u554a

You can use fmt.Sprintf along with %U to get the hexadecimal value:

test = fmt.Sprintf("%U", '啊')
fmt.Println("\\u" + test[2:]) // Print \u554A

fmt.Printf("\\u%X", '啊')

http://play.golang.org/p/Jh9ns8Qh15

(Upper or lowercase 'x' will control the case of the hex characters)

As hinted at by package fmt's documentation:

%U Unicode format: U+1234; same as "U+%04X"

I'd like to add to the answer that hardPass has.

In the case where the hex representation of the unicode is less that 4 characters (ü for example) strconv.FormatInt will result in \ufc which will result in a unicode syntax error in Go. As opposed to the full \u00fc that Go understands.

Padding the hex with zeros using fmt.Sprintf with hex formatting will fix this:

func RuneToAscii(r rune) string {
    if r < 128 {
        return string(r)
    } else {
        return fmt.Sprintf("\\u%04x", r)
    }
}

https://play.golang.org/p/80w29oeBec1

This would do the job..

package main

import (
    "fmt"
)

func main() {
    str := fmt.Sprintf("%s", []byte{0x80})
    fmt.Println(str)
}

package main

import "fmt"

func main() {
    fmt.Printf("%+q", '啊')
}