Added book examples

C9/while_loop.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+   	int age = 1;  			// Declare variable and initialise to 1
+    
+    while ( age != 0)	    // Loop as long as age is not zero
+    {
+        // Code in {} executed if condition is true (non-zero)
+        
+        printf ("\nPlease enter your age");
+        scanf("%d", &age);
+        printf ("You are %d years old\n", age);    
+        
+        // Code  now goes back and repeats the test with the value of age just entered
+    }
+    return 0;	// Exit code
+}