finished ch3

loops/src/main.rs

@@ -1,6 +1,7 @@
+
 fn main() {
     println!("Hello, world!");
-    looping_through_a_list();
+    looping_through_a_list_with_rev();
 }
 
 // rust has 3 types of loops: loop, while and for
@@ -72,9 +73,37 @@ fn looping_through_a_list () {
     let mut index = 0;
     // if a.len was a static number this would/could cause the program to panic 
     // because if a was modified and the static number was not then it would attempt to go out out the assigned memory
+    // compiler will add code to check if static number is within the bounds and therefore is slower
     // using list.len() is always a better solution
     while index < a.len() {
         println!("the value is: {}", a[index]);
         index += 1;
     }
-}
+}
+
+// for loops are the most safe and easy to use
+
+fn looping_through_a_list_more_concise_and_secure () {
+    let b = [32, 5, 6, 79, 88, 99];
+    // is is more safe and is faster than even a.len() no operation for checking the size everytime/re-eval the bool
+    // removed chance of bug in static number and is faster
+    for element in b {
+        println!("the value is {}", element);
+    }
+    // Ranges are start..end not Range(5), that range method/funct is fake
+    for num in 0..5 {
+        println!("the value is now: {}", num);
+    }
+
+
+}
+
+
+fn looping_through_a_list_with_rev () {
+    // this reverse the order of a range
+    for number in (1..4).rev() {
+        println!("{}!", number);
+    }
+
+    println!("Lift-Off!!");
+}