Go言語_rune

rune.go

package try

import "fmt"

func Run_Rune() {
	Rune("Hello,世界!")
}

func Rune(s string) {
	str := []rune(s) // str []rune
	for i, r := range str {
		fmt.Printf("i%d r %c\n", i, r)
	}
	fmt.Println("------")
	for i, v := range s { // var v rune
		fmt.Printf("i%d r %c\n", i, v)
	}
}

実行結果

@Mac feb_twelve % go version
go version go1.14.1 darwin/amd64
@Mac feb_twelve % sw_vers
ProductName:    macOS
ProductVersion: 12.1
BuildVersion:   21C52
@Mac feb_twelve % tree
.
├── go.mod
├── main.go
└── try
    └── rune.go

@Mac feb_twelve % go run main.go
i0 r H
i1 r e
i2 r l
i3 r l
i4 r o
i5 r ,
i6 r 世
i7 r 界
i8 r !
------
i0 r H
i1 r e
i2 r l
i3 r l
i4 r o
i5 r ,
i6 r 世
i9 r 界
i12 r !
@Mac feb_twelve %

解説

.goenv/versions/1.14.1/src/builtin/builtin.go

// rune is an alias for int32
type rune = int32

To make things dependable, there are normalization techniques that guarantee that a given character is always represented by the same code points
~
“Code point” is a bit of a mouthful, so Go introduces a shorter term for the concept: rune
by The Go Blog

参考

Slice string into letters - stackoverflow
Strings, bytes, runes and characters in Go - The Go Blog