utf-8 - 截断 UTF 字符串中的最后一个 rune

Question

如何截断UTF字符串中的最后一个 rune ？ 这种方法显然是错误的:

package main

import ("fmt"
 "unicode/utf8")

func main() {
    string := "你好"
    length := utf8.RuneCountInString(string)
    // how to cut off last rune in UTF string? 
    // this method is obviously incorrect:
    withoutLastRune := string[0:length-1]
    fmt.Println(withoutLastRune)
}

Playground

Answer 1

差不多

utf8 包有一个函数可以解码字符串中的最后一个 rune ，该函数还返回其长度。从末尾剪掉这个字节数，你就成功了:

str := "你好"
_, lastSize := utf8.DecodeLastRuneInString(str)
withoutLastRune := str[:len(str)-lastSize]
fmt.Println(withoutLastRune)

playground