update dir

static/static_demo.cpp

@@ -0,0 +1,24 @@
+// the use of static Static 
+// variables in a Function 
+#include <iostream> 
+#include <string> 
+using namespace std; 
+
+void demo() 
+{ 
+    // static variable 
+    static int count = 0; 
+    cout << count << " "; 
+
+    // value is updated and 
+    // will be carried to next 
+    // function calls 
+    count++; 
+} 
+
+int main() 
+{ 
+    for (int i=0; i<5; i++)  
+        demo(); 
+    return 0; 
+}