From b0a83f934ea40a6dd10df824cec19350efc9a41d Mon Sep 17 00:00:00 2001
From: GO <go@go.jdg>
Date: Tue, 7 Sep 2021 19:55:43 +0000
Subject: [PATCH] testing

---
 hello/hello.go                    |  8 ++++++--
 hello/morestrings/reverse.go      | 12 ++++++++++++
 hello/morestrings/reverse_test.go | 19 +++++++++++++++++++
 range/range.go                    | 31 +++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 hello/morestrings/reverse.go
 create mode 100644 hello/morestrings/reverse_test.go
 create mode 100644 range/range.go

diff --git a/hello/hello.go b/hello/hello.go
index 91cca4f..a56548d 100644
--- a/hello/hello.go
+++ b/hello/hello.go
@@ -1,7 +1,11 @@
 package main
 
-import "fmt"
+import (
+        "fmt"
+        "c.infdj.com/GO/courses_golang/hello/morestrings"
+)
 
 func main() {
-	fmt.Println("Hello, world.")
+        // fmt.Println("Hello, world.")
+        fmt.Println(morestrings.ReverseRunes("!oG ,olleH"))
 }
diff --git a/hello/morestrings/reverse.go b/hello/morestrings/reverse.go
new file mode 100644
index 0000000..7f4e24c
--- /dev/null
+++ b/hello/morestrings/reverse.go
@@ -0,0 +1,12 @@
+// Package morestrings implements additional functions to manipulate UTF-8
+// encoded strings, beyond what is provided in the standard "strings" package.
+package morestrings
+
+// ReverseRunes returns its argument string reversed rune-wise left to right.
+func ReverseRunes(s string) string {
+	r := []rune(s)
+	for i, j := 0, len(r)-1; i < len(r)/2; i, j = i+1, j-1 {
+		r[i], r[j] = r[j], r[i]
+	}
+	return string(r)
+}
diff --git a/hello/morestrings/reverse_test.go b/hello/morestrings/reverse_test.go
new file mode 100644
index 0000000..9a76ef8
--- /dev/null
+++ b/hello/morestrings/reverse_test.go
@@ -0,0 +1,19 @@
+package morestrings
+
+import "testing"
+
+func TestReverseRunes(t *testing.T) {
+	cases := []struct {
+		in, want string
+	}{
+		{"Hello, world", "dlrow ,olleH"},
+		{"Hello, 世界", "界世 ,olleH"},
+		{"", ""},
+	}
+	for _, c := range cases {
+		got := ReverseRunes(c.in)
+		if got != c.want {
+			t.Errorf("ReverseRunes(%q) == %q, want %q", c.in, got, c.want)
+		}
+	}
+}
diff --git a/range/range.go b/range/range.go
new file mode 100644
index 0000000..2b06503
--- /dev/null
+++ b/range/range.go
@@ -0,0 +1,31 @@
+package main
+
+import "fmt"
+
+func main() {
+	nums := []int{2, 3, 4}
+	sum := 0
+	for _, num := range nums {
+		sum += num
+	}
+	fmt.Println("sum:",sum)
+
+	for i,num := range nums {
+		if num == 3 {
+			fmt.Println("index:",i)
+		}
+	}
+
+	kvs := map[string]string{"a":"apple", "b":"banana"}
+	for k, v := range kvs {
+		fmt.Printf("%s -> %s\n", k, v)
+	}
+	
+	for k := range kvs {
+		fmt.Println("key:", k)
+	}
+
+	for i,c := range "go" {
+		fmt.Println(i,c)
+	}
+}