Completed exercise up to Traits

exercises/12_options/options1.rs

@@ -3,7 +3,22 @@
 // someone eats it all, so no ice cream is left (value 0). Return `None` if
 // `hour_of_day` is higher than 23.
 fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
-    // TODO: Complete the function body.
+    if hour_of_day > 23 {
+        None
+    } else if hour_of_day < 22 {
+            Some(5)
+        } else {
+            Some(0)
+        }
+
+    // OR
+    // fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
+    //     match hour_of_day {
+    //         0..=21 => Some(5),
+    //         22 | 23 => Some(0),
+    //         _ => None,
+    //     }
+    // }    
 }
 
 fn main() {
@@ -20,7 +35,7 @@ mod tests {
         // Option?
         let ice_creams = maybe_ice_cream(12);
 
-        assert_eq!(ice_creams, 5); // Don't change this line.
+        assert_eq!(ice_creams, Some(5)); // Don't change this line.
     }
 
     #[test]

exercises/12_options/options2.rs

@@ -10,7 +10,10 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if-let statement whose value is `Some`.
-        word = optional_target {
+        // word = optional_target {
+        //     assert_eq!(word, target);
+        // }
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
     }
@@ -29,10 +32,16 @@ mod tests {
         // TODO: Make this a while-let statement. Remember that `Vec::pop()`
         // adds another layer of `Option`. You can do nested pattern matching
         // in if-let and while-let statements.
-        integer = optional_integers.pop() {
-            assert_eq!(integer, cursor);
-            cursor -= 1;
+        while let Some(integer) = optional_integers.pop() {
+            if let Some(integer_value) = integer {
+                println!("integer_value (left): {}, cursor (right): {}", integer_value, cursor);
+                assert_eq!(integer_value, cursor);
+                cursor -= 1;
+            } else {
+                println!("None value, cursor: {}", cursor);
+            }
         }
+        
 
         assert_eq!(cursor, 0);
     }

exercises/12_options/options3.rs

@@ -9,7 +9,7 @@ fn main() {
 
     // TODO: Fix the compiler error by adding something to this match statement.
     match optional_point {
-        Some(p) => println!("Coordinates are {},{}", p.x, p.y),
+        Some(ref p) => println!("Coordinates are {},{}", p.x, p.y),
         _ => panic!("No match!"),
     }