functions

.rustlings-state.txt

@@ -1,6 +1,17 @@
 DON'T EDIT THIS FILE!
 
-variables1
+if1
 
 intro1
-intro2
+intro2
+variables1
+variables2
+variables3
+variables4
+variables5
+variables6
+functions1
+functions2
+functions3
+functions4
+functions5

exercises/01_variables/variables1.rs

@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Add the missing keyword.
-    x = 5;
+    let x = 5;
 
     println!("x has the value {x}");
 }

exercises/01_variables/variables2.rs

@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Change the line below to fix the compiler error.
-    let x;
+    let x = 10;
 
     if x == 10 {
         println!("x is ten!");

exercises/01_variables/variables3.rs

@@ -1,6 +1,6 @@
 fn main() {
     // TODO: Change the line below to fix the compiler error.
-    let x: i32;
+    let x: i32 = 10;
 
     println!("Number {x}");
 }

exercises/01_variables/variables4.rs

@@ -1,6 +1,6 @@
 // TODO: Fix the compiler error.
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {x}");
 
     x = 5; // Don't change this line

exercises/01_variables/variables5.rs

@@ -3,6 +3,6 @@ fn main() {
     println!("Spell a number: {number}");
 
     // TODO: Fix the compiler error by changing the line below without renaming the variable.
-    number = 3;
+    let number = 3;
     println!("Number plus two is: {}", number + 2);
 }

exercises/01_variables/variables6.rs

@@ -1,5 +1,5 @@
 // TODO: Change the line below to fix the compiler error.
-const NUMBER = 3;
+const NUMBER: i32 = 3;
 
 fn main() {
     println!("Number: {NUMBER}");

exercises/02_functions/functions1.rs

@@ -1,5 +1,8 @@
 // TODO: Add some function with the name `call_me` without arguments or a return value.
 
+fn call_me() {
+    println!("I was called!");
+}
 fn main() {
     call_me(); // Don't change this line
 }

exercises/02_functions/functions2.rs

@@ -1,5 +1,5 @@
 // TODO: Add the missing type of the argument `num` after the colon `:`.
-fn call_me(num:) {
+fn call_me(num: i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/02_functions/functions3.rs

@@ -6,5 +6,5 @@ fn call_me(num: u8) {
 
 fn main() {
     // TODO: Fix the function call.
-    call_me();
+    call_me(1);
 }

exercises/02_functions/functions4.rs

@@ -8,7 +8,7 @@ fn is_even(num: i64) -> bool {
 }
 
 // TODO: Fix the function signature.
-fn sale_price(price: i64) -> {
+fn sale_price(price: i64) -> i64 {
     if is_even(price) {
         price - 10
     } else {

exercises/02_functions/functions5.rs

@@ -1,6 +1,6 @@
 // TODO: Fix the function body without changing the signature.
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
 
 fn main() {

solutions/01_variables/variables1.rs

@@ -1,4 +1,6 @@
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // Declaring variables requires the `let` keyword.
+    let x = 5;
+
+    println!("x has the value {x}");
 }

solutions/02_functions/functions1.rs

@@ -1,4 +1,8 @@
+// Some function with the name `call_me` without arguments or a return value.
+fn call_me() {
+    println!("Hello world!");
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    call_me();
 }

solutions/02_functions/functions2.rs

@@ -1,4 +1,11 @@
+// The type of function arguments must be annotated.
+// Added the type annotation `u64`.
+fn call_me(num: u64) {
+    for i in 0..num {
+        println!("Ring! Call number {}", i + 1);
+    }
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    call_me(3);
 }

solutions/02_functions/functions3.rs

@@ -1,4 +1,10 @@
+fn call_me(num: u8) {
+    for i in 0..num {
+        println!("Ring! Call number {}", i + 1);
+    }
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // `call_me` expects an argument.
+    call_me(5);
 }

solutions/02_functions/functions4.rs

@@ -1,4 +1,17 @@
+fn is_even(num: i64) -> bool {
+    num % 2 == 0
+}
+
+// The return type must always be annotated.
+fn sale_price(price: i64) -> i64 {
+    if is_even(price) {
+        price - 10
+    } else {
+        price - 3
+    }
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    let original_price = 51;
+    println!("Your sale price is {}", sale_price(original_price));
 }

solutions/02_functions/functions5.rs

@@ -1,4 +1,9 @@
+fn square(num: i32) -> i32 {
+    // Removed the semicolon `;` at the end of the line below to implicitly return the result.
+    num * num
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    let answer = square(3);
+    println!("The square of 3 is {answer}");
 }