better time and file examples

Author: SimonWaldherr

beginner/file.go

@@ -2,7 +2,7 @@ package main
 
 import "os"
 
-// OpenCreateFile open an existed file or create a file if not exists
+// OpenCreateFile opens an existing file or creates a new file if it does not exist
 func OpenCreateFile(path string) *os.File {
 	if _, err := os.Stat(path); os.IsNotExist(err) {
 		f, err := os.Create(path)

beginner/file02.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+)
+
+func write() {
+	content := []byte("Hello, Golang!")
+	err := ioutil.WriteFile("example.txt", content, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func read() {
+	content, err := ioutil.ReadFile("example.txt")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("File content: %s\n", content)
+}
+
+func main() {
+	write()
+	read()
+}

beginner/time.go

@@ -7,6 +7,10 @@ import (
 )
 
 func main() {
+	start := time.Now()
+	fmt.Println("Current time:", start)
+	//Current time: 2023-04-05 19:43:23.329968 +0200 CEST m=+0.000140960
+
 	fmt.Println(strconv.FormatInt(time.Now().Unix(), 10))
 	//1401403874
 	fmt.Println(time.Now().Format(time.RFC850))
@@ -21,4 +25,8 @@ func main() {
 	//1973-11-29T22:33:09+01:00
 	fmt.Println(time.Unix(1234567890, 0).Format(time.RFC822))
 	//14 Feb 09 00:31 CET
+
+	elapsed := time.Since(start)
+	fmt.Println("Time elapsed:", elapsed)
+	//Time elapsed: 428.458µs
 }