sdf

go_book/proj1/go.mod

@@ -1,3 +1,5 @@
 module proj1
 
 go 1.24.5
+
+require go.uber.org/zap v1.27.1

go_book/proj1/go.sum

@@ -0,0 +1,2 @@
+go.uber.org/zap v1.27.1 h1:08RqriUEv8+ArZRYSTXy1LeBScaMpVSTBhCeaZYfMYc=
+go.uber.org/zap v1.27.1/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=

go_book/proj1/main.go

@@ -2,13 +2,29 @@ package main
 
 import (
 	"fmt"
-	"os"
-	// "strings"
+	"strconv"
+	"go.uber.org/zap/buffer"
 )
 
+func addCommas(n int) string {
+    str := strconv.Itoa(n)
+    
+    // Add commas from right to left
+    var result buffer.Buffer
+    for i := range str {
+        if i > 0 && (len(str)-i)%3 == 0 {
+				 fmt.Fprint(&result,",")
+        }
+        result.WriteByte(str[i])
+    }
+    
+    return result.String()
+}
+
 func main() {
-	// var sum string
-	for key,val := range os.Args[:]{
-		fmt.Println("num is",key,"value is", val)
-	}
+    numbers := []int{12345, 1234567, 987654321, 12345, 123, 0}
+    
+    for _, num := range numbers {
+        fmt.Printf("%d -> %s\n", num, addCommas(num))
+    }
 }