Strings, bytes, runes and characters in Go

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1 Printing strings

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package main

import "fmt"

func main() {
  const sample = "\xbd\xb2\x3d\xbc\x20\xe2\x8c\x98"

  fmt.Println("Println:")
  fmt.Println(sample)

  fmt.Println("Byte loop:")
  for i := 0; i < len(sample); i++ {
    fmt.Printf("%x ", sample[i])
  }
  fmt.Printf("\n")

  fmt.Println("Printf with %x:")
  fmt.Printf("%x\n", sample)

  fmt.Println("Printf with % x:")
  fmt.Printf("% x\n", sample)

  fmt.Println("Printf with %q:")
  fmt.Printf("%q\n", sample)

  fmt.Println("Printf with %+q:")
  fmt.Printf("%+q\n", sample)

  fmt.Println("Byte loop with %q:")
  for i := 0; i < len(sample); i++ {
    fmt.Printf("%q ", sample[i])
  }
  fmt.Printf("\n")
}

2 UTF-8 and string literals

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package main

import "fmt"

func main() {
  const placeOfInterest = `⌘`

  fmt.Printf("plain string: ")
  fmt.Printf("%s", placeOfInterest)
  fmt.Printf("\n")

  fmt.Printf("quoted string: ")
  fmt.Printf("%+q", placeOfInterest)
  fmt.Printf("\n")

  fmt.Printf("hex bytes: ")
  for i := 0; i < len(placeOfInterest); i++ {
    fmt.Printf("%x ", placeOfInterest[i])
  }
  fmt.Printf("\n")
}
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package main

import "fmt"

func main() {
  const nihongo = "日本語"
  for index, runeValue := range nihongo {
    fmt.Printf("%#U starts at byte position %d\n", runeValue, index)
  }

  const str = "abc"
  for index, runeValue := range str {
    fmt.Printf("%#U starts at byte position %d\n", runeValue, index)
  }
}
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package main

import (
  "fmt"
  "unicode/utf8"
)

func main() {
  const nihongo = "日本語"
  for i, w := 0, 0; i < len(nihongo); i += w {
    runeValue, width := utf8.DecodeRuneInString(nihongo[i:])
    fmt.Printf("%#U starts at byte position %d\n", runeValue, i)
    w = width
  }
}
Last Updated 2018-04-08 Sun 18:24.
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