The Go Programming Language

by Alan A.A. Donovan

On the other hand, if we really care about the individual Unicode characters, we have to use other mechanisms. Consider the string from our very first example, which includes two East Asian characters. Figure 3.5 illustrates its representation in memory. The string contains 13 bytes, but interpreted as UTF-8, it encodes only nine code points or runes: Figure 3.5. A range loop decodes a UTF-8-encoded string. Click here to view code image import "unicode/utf8" s := "Hello, " fmt.Println(len(s)) // "13" fmt.Println(utf8.RuneCountInString(s)) // "9" To process those characters, we need a UTF-8 decoder. The unicode/utf8 package provides one that we can use like this: Click here to view code image for i := 0; i < len(s); { r, size := utf8.DecodeRuneInString(s[i:]) fmt.Printf("%d\t%c\n", i, r) i += size }