Add pointer and password app

go-demo-4/go.mod

@@ -0,0 +1,3 @@
+module password
+
+go 1.23.6

go-demo-4/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	a := [4]int{1, 2, 3, 4}
+	reverse(&a)
+	fmt.Println(a)
+
+	var n *int
+	fmt.Println(*n)
+}
+
+func reverse(arr *[4]int) {
+	for idx, val := range *arr {
+		(*arr)[len(arr)-1-idx] = val
+	}
+}

go-demo-4/pointers/main.go

@@ -0,0 +1,15 @@
+package pointers
+
+import "fmt"
+
+func main() {
+	a := 5
+	pointerA := &a
+	double(&a)
+	fmt.Println(*pointerA) // Дереференс (разыменование) указателя
+	fmt.Println(a)
+}
+
+func double(num *int) {
+	*num = *num * 2
+}