add: string quiz + execises

19-strings-runes-bytes/exercises/03-rune-manipulator/solution/main.go

@@ -0,0 +1,78 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"unicode/utf8"
+)
+
+func main() {
+	strings := []string{
+		"cool",
+		"güzel",
+		"jīntiān",
+		"今天",
+		"read 🤓",
+	}
+
+	for _, s := range strings {
+		fmt.Printf("%q\n", s)
+
+		// Print the byte and rune length of the strings
+		// Hint: Use len and utf8.RuneCountInString
+		fmt.Printf("\thas %d bytes and %d runes\n",
+			len(s), utf8.RuneCountInString(s))
+
+		// Print the bytes of the strings in hexadecimal
+		// Hint: Use % x verb
+		fmt.Printf("\tbytes   : % x\n", s)
+
+		// Print the runes of the strings in hexadecimal
+		// Hint: Use % x verb
+		fmt.Print("\trunes   :")
+		for _, r := range s {
+			fmt.Printf("% x", r)
+		}
+		fmt.Println()
+
+		// Print the runes of the strings as rune literals
+		// Hint: Use for range
+		fmt.Print("\trunes   :")
+		for _, r := range s {
+			fmt.Printf("%q", r)
+		}
+		fmt.Println()
+
+		// Print the first rune and its byte size of the strings
+		// Hint: Use utf8.DecodeRuneInString
+		r, size := utf8.DecodeRuneInString(s)
+		fmt.Printf("\tfirst   : %q (%d bytes)\n", r, size)
+
+		// Print the last rune of the strings
+		// Hint: Use utf8.DecodeLastRuneInString
+		r, size = utf8.DecodeLastRuneInString(s)
+		fmt.Printf("\tfirst   : %q (%d bytes)\n", r, size)
+
+		// Slice and print the first two runes of the strings
+		_, first := utf8.DecodeRuneInString(s)
+		_, second := utf8.DecodeRuneInString(s[first:])
+		fmt.Printf("\tfirst 2 : %q\n", s[:first+second])
+
+		// Slice and print the last two runes of the strings
+		_, last1 := utf8.DecodeLastRuneInString(s)
+		_, last2 := utf8.DecodeLastRuneInString(s[:len(s)-last1])
+		fmt.Printf("\tlast 2  : %q\n", s[len(s)-last2-last1:])
+
+		// Convert the string to []rune
+		// Print the first and last two runes
+		rs := []rune(s)
+		fmt.Printf("\tfirst 2 : %q\n", string(rs[:2]))
+		fmt.Printf("\tlast 2  : %q\n", string(rs[len(rs)-2:]))
+	}
+}