what is rune in go

Like other programming languages golang doesn't have character type.

So how are characters represented in a string?

ASCII charters in a string are represented by a Byte.
UNICODE characters in a string are represented by a RUNE.

In reality they are both just aliases for integer types (uint8 and int32).

if you want to force them to be printed as characters instead of numbers, you need to use Printf("%c", x). The %c format specification works for any integer type.

In the below program, the rune function is used to return the right character representation of an String based on the underlying storage (uint8,int32) .

package main

import "fmt"

func main() {
    fmt.Println(string([]rune("Hello, 日本語")[1])) // UTF-8
    fmt.Println(string([]rune("Hello, 日本語")[8])) // UTF-8}