if3 solution

exercises/03_if/if3.rs

@@ -1,4 +1,5 @@
-fn animal_habitat(animal: &str) -> &'static str {
+fn animal_habitat(animal: &str) -> &str {
+    // TODO: Fix the compiler error in the statement below.
     let identifier = if animal == "crab" {
         1
     } else if animal == "gopher" {
@@ -9,8 +10,8 @@ fn animal_habitat(animal: &str) -> &'static str {
         "Unknown"
     };
 
-    // DO NOT CHANGE THIS STATEMENT BELOW
-    let habitat = if identifier == 1 {
+    // Don't change the expression below!
+    if identifier == 1 {
         "Beach"
     } else if identifier == 2 {
         "Burrow"
@@ -18,37 +19,35 @@ fn animal_habitat(animal: &str) -> &'static str {
         "Desert"
     } else {
         "Unknown"
-    };
-
-    habitat
+    }
 }
 
 fn main() {
     // You can optionally experiment here.
 }
 
-// No test changes needed.
+// Don't change the tests!
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
     fn gopher_lives_in_burrow() {
-        assert_eq!(animal_habitat("gopher"), "Burrow");
+        assert_eq!(animal_habitat("gopher"), "Burrow")
     }
 
     #[test]
     fn snake_lives_in_desert() {
-        assert_eq!(animal_habitat("snake"), "Desert");
+        assert_eq!(animal_habitat("snake"), "Desert")
     }
 
     #[test]
     fn crab_lives_on_beach() {
-        assert_eq!(animal_habitat("crab"), "Beach");
+        assert_eq!(animal_habitat("crab"), "Beach")
     }
 
     #[test]
     fn unknown_animal() {
-        assert_eq!(animal_habitat("dinosaur"), "Unknown");
+        assert_eq!(animal_habitat("dinosaur"), "Unknown")
     }
 }

solutions/03_if/if3.rs

@@ -1 +1,53 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+fn animal_habitat(animal: &str) -> &str {
+    let identifier = if animal == "crab" {
+        1
+    } else if animal == "gopher" {
+        2
+    } else if animal == "snake" {
+        3
+    } else {
+        // Any unused identifier.
+        4
+    };
+
+    // Instead of such an identifier, you would use an enum in Rust.
+    // But we didn't get into enums yet.
+    if identifier == 1 {
+        "Beach"
+    } else if identifier == 2 {
+        "Burrow"
+    } else if identifier == 3 {
+        "Desert"
+    } else {
+        "Unknown"
+    }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn gopher_lives_in_burrow() {
+        assert_eq!(animal_habitat("gopher"), "Burrow")
+    }
+
+    #[test]
+    fn snake_lives_in_desert() {
+        assert_eq!(animal_habitat("snake"), "Desert")
+    }
+
+    #[test]
+    fn crab_lives_on_beach() {
+        assert_eq!(animal_habitat("crab"), "Beach")
+    }
+
+    #[test]
+    fn unknown_animal() {
+        assert_eq!(animal_habitat("dinosaur"), "Unknown")
+    }
+}