Added book examples

C9/do_while_loop.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+	int age;		// Declare variable, no need to initialise this time 
+					// as we read into it before it is tested against
+    
+    // The loop is always entered as the test is at the end
+    do 
+    {
+        // Code must be executed at least once
+        printf ("\nPlease enter your age");
+        scanf("%d", &age);
+        printf ("You are %d years old\n", age);    
+        
+        // Test is now made and the code 
+        // repeats if the test equates as non-zerp
+        // (i.e. is age is not zero)
+    }
+    while ( age != 0);
+    
+    return 0;
+}