❯ go run ./main.go
String: Hello, 世界
Rune at position 0: H
Rune at position 1: e
Rune at position 2: l
Rune at position 3: l
Rune at position 4: o
Rune at position 5: ,
Rune at position 6:  
Rune at position 7: 世
Rune at position 10: 界
Byte at position 0: 48
Byte at position 1: 65
Byte at position 2: 6c
Byte at position 3: 6c
Byte at position 4: 6f
Byte at position 5: 2c
Byte at position 6: 20
Byte at position 7: e4
Byte at position 8: b8
Byte at position 9: 96
Byte at position 10: e7
Byte at position 11: 95
Byte at position 12: 8c