Add solutions to functions

exercises/02_functions/functions1.rs

@@ -1,3 +1,5 @@
+// TODO: Add some function with the name `call_me` without arguments or a return value.
+
 fn main() {
-    call_me();
+    call_me(); // Don't change this line
 }

exercises/02_functions/functions2.rs

@@ -1,9 +1,10 @@
-fn main() {
-    call_me(3);
-}
-
+// TODO: Add the missing type of the argument `num` after the colon `:`.
 fn call_me(num:) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }
 }
+
+fn main() {
+    call_me(3);
+}

exercises/02_functions/functions3.rs

@@ -1,9 +1,10 @@
-fn main() {
-    call_me();
-}
-
 fn call_me(num: u32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }
 }
+
+fn main() {
+    // TODO: Fix the function call.
+    call_me();
+}

exercises/02_functions/functions4.rs

@@ -1,14 +1,14 @@
 // This store is having a sale where if the price is an even number, you get 10
-// Rustbucks off, but if it's an odd number, it's 3 Rustbucks off. (Don't worry
-// about the function bodies themselves, we're only interested in the signatures
-// for now. If anything, this is a good way to peek ahead to future exercises!)
+// Rustbucks off, but if it's an odd number, it's 3 Rustbucks off.
+// Don't worry about the function bodies themselves, we are only interested in
+// the signatures for now.
 
-fn main() {
-    let original_price = 51;
-    println!("Your sale price is {}", sale_price(original_price));
+fn is_even(num: i64) -> bool {
+    num % 2 == 0
 }
 
-fn sale_price(price: i32) -> {
+// TODO: Fix the function signature.
+fn sale_price(price: i64) -> {
     if is_even(price) {
         price - 10
     } else {
@@ -16,6 +16,7 @@ fn sale_price(price: i32) -> {
     }
 }
 
-fn is_even(num: i32) -> bool {
-    num % 2 == 0
+fn main() {
+    let original_price = 51;
+    println!("Your sale price is {}", sale_price(original_price));
 }

exercises/02_functions/functions5.rs

@@ -1,8 +1,9 @@
-fn main() {
-    let answer = square(3);
-    println!("The square of 3 is {}", answer);
-}
-
+// TODO: Fix the function body without chaning the signature.
 fn square(num: i32) -> i32 {
     num * num;
 }
+
+fn main() {
+    let answer = square(3);
+    println!("The square of 3 is {answer}");
+}