Golang : Extract unicode string from another unicode string example

Problem:

You have a string with unicode (UTF-8) characters and you want to extract part of the string by using character indexing. However, the output result is weird. What is the correct way to extract unicode (UTF-8) characters from a string?

Solution:

Wrap the string with []rune, then index the characters and finally the convert the rune bytes to string.

Here you go!

 package main

 import "fmt"

 func main() {
  // wrong way
  fmt.Println("fuß is german language for foot"[1])

  // wrong way
  fmt.Println(string("fuß is german language for foot"[1]))

  // correct way
  fmt.Println(string([]rune("fuß is german language for foot")[0:3]))

  // correct way
  fmt.Println(string([]rune("腳 is chinese language for foot")[0:1]))

 }

Output:

117

u

fuß

腳

alternatively, you can use the strings.SplitN() function as well.

 package main

 import (
  "fmt"
  "strings"
 )

 func main() {
  str := "腳 is chinese language for foot"

  // extract each word from str
  parts := strings.SplitN(str, " ", -1)

  fmt.Println(parts[0])

  fmt.Println(parts[1])

  fmt.Println(parts[2])

  fmt.Println(parts[3])

  fmt.Println(parts[4])

  fmt.Println(parts[5])

 }

Output:

腳

is

chinese

language

for

foot

Happy coding!

References:

https://golang.org/ref/spec#Index_expressions

https://www.socketloop.com/tutorials/golang-get-first-few-and-last-few-characters-from-string

https://www.socketloop.com/tutorials/golang-extract-sub-strings