slice

slice/append/main.go

@@ -0,0 +1,27 @@
+package main
+
+import "fmt"
+
+func main() {
+	case1()
+	case2()
+}
+
+// 当capacity
+func case1() {
+	s1 := make([]string, 1, 20)
+	s1[0] = "hello"
+	p1 := &s1[0]
+	s1 = append(s1, "world")
+	*p1 = "hello2"
+	fmt.Printf("value of p1 is %s, value of s1[0] is %s \n", *p1, s1[0])
+}
+
+func case2() {
+	s1 := make([]string, 1)
+	s1[0] = "hello"
+	p1 := &s1[0]
+	s1 = append(s1, "world")
+	*p1 = "hello2"
+	fmt.Printf("value of p1 is %s, value of s1[0] is %s \n", *p1, s1[0])
+}

slice/rune/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"fmt"
+	"unicode/utf8"
+)
+
+func main() {
+	s := "中文, hello world"
+
+	for i, r := range s {
+		rl := utf8.RuneLen(r)
+		offset := i + rl
+		fmt.Printf("codepoint: %#6x; offset: %d, char %s\n", r, offset, s[i:i+rl])
+	}
+
+}