How to select a substring of a utf8 string on GO?

Question

go

slash := "I'm a UTF8 STRING GET A SUBSTRING FROM ME" I
want to get a substring, the standard cut works by bytes, so nothing worthwhile happens.
Another question is whether it is possible to immediately create a string, each character of which is 4 bytes, so that you can safely get the desired character by index, or is there another way?

Answer 1

str := `I am a UTF8 STRING GET A SUBSTRING FROM ME`
fmt.Println(string([]rune(str)[5:9]))