add: strings and projects

19-strings-runes-bytes/05-internals/main.go

@@ -0,0 +1,45 @@
+// 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"
+	"unsafe"
+)
+
+func main() {
+	// empty := ""
+	// dump(empty)
+
+	hello := "hello"
+	dump(hello)
+	dump("hello")
+	dump("hello!")
+
+	for i := range hello {
+		dump(hello[i : i+1])
+	}
+
+	dump(string([]byte(hello)))
+	dump(string([]byte(hello)))
+	dump(string([]rune(hello)))
+}
+
+// StringHeader is used by a string value
+// In practice, you should use: reflect.Header
+type StringHeader struct {
+	// points to a backing array's item
+	pointer uintptr // where it starts
+	length  int     // where it ends
+}
+
+// dump prints the string header of a string value
+func dump(s string) {
+	ptr := *(*StringHeader)(unsafe.Pointer(&s))
+	fmt.Printf("%q: %+v\n", s, ptr)
+}