Skip non-printable characters in Go

💻 Tech

If you’re traversing a slice of bytes of string in Go, and you want to decode each byte into a rune, it’s possible to encounter a non-printable character. For example, if you’re using %c directive in a for loop, the iteration with a non-printable character will be skipped. To check if a character is printable, you can use the unicode.IsPrint function. Here’s an example:

s := "Hello ☺"
for _, r := range s {
    if unicode.IsPrint(r) {
        fmt.Printf("%c", r)
    }
}

One real-world example where it happens is when you try to decode a byte that is part of a multi-byte character. For example, smiley face ☺ occupies 3 bytes in UTF-8 encoding.