Added book examples

C19/static_variable_example.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void DisplayHelloWorld (void)
+{
+    static int k = 0;       // Counter for how many times the function is called
+
+    printf ("Hello World\n");
+
+    // Increment counter and display value
+    k = k + 1;
+    printf ("I have now said this %d times\n",k);
+}
+// Main () - execution starts here
+int main (void)
+{
+    int i;
+
+    // Loop calling out function 10 times
+    for ( i =0 ; i < 10 ; i++ )
+    {
+        DisplayHelloWorld();
+    }
+
+    return (0);     // Exit indicating success
+}