Inital commit of learning Rust

exercises/functions/functions1.rs

@@ -1,8 +1,11 @@
 // functions1.rs
 // Make me compile! Execute `rustlings hint functions1` for hints :)
 
-// I AM NOT DONE
+// This needed the call_me fucntion to be defined.
 
 fn main() {
+    fn call_me() {
+        println!("Hello World");
+    }
     call_me();
 }

exercises/functions/functions2.rs

@@ -1,13 +1,12 @@
 // functions2.rs
 // Make me compile! Execute `rustlings hint functions2` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+// Below I added the i32, beacuse the function expected a type to set/specified.
+fn call_me(num: i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/functions/functions3.rs

@@ -1,10 +1,9 @@
 // functions3.rs
 // Make me compile! Execute `rustlings hint functions3` for hints :)
 
-// I AM NOT DONE
+// Need to pass in an unsigned 32 bit num to get this to work.
-
 fn main() {
-    call_me();
+    call_me(10);
 }
 
 fn call_me(num: u32) {

exercises/functions/functions4.rs

@@ -4,14 +4,14 @@
 // 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.
 
-// I AM NOT DONE
-
 fn main() {
     let original_price = 51;
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> {
+// Below I needed to specify a type for the return item
+// This happened to be a i32
+fn sale_price(price: i32) -> i32 {
     if is_even(price) {
         price - 10
     } else {

exercises/functions/functions5.rs

@@ -1,13 +1,12 @@
 // functions5.rs
 // Make me compile! Execute `rustlings hint functions5` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = square(3);
     println!("The answer is {}", answer);
 }
 
+// This  funtion implicitly returns, there is no need for the ; after num * num
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/if/if1.rs

@@ -1,13 +1,17 @@
 // if1.rs
 
-// I AM NOT DONE
-
 pub fn bigger(a: i32, b: i32) -> i32 {
     // Complete this function to return the bigger number!
     // Do not use:
     // - another function call
     // - additional variables
     // Execute `rustlings hint if1` for hints
+    if a > b {
+        a
+    } else {
+        b
+    }
+    // No need for a return a; these fucnitons implictily return!
 }
 
 // Don't mind this for now :)

exercises/intro/intro1.rs

@@ -5,7 +5,6 @@
 // ready for the next exercise, remove the `I AM NOT DONE` comment below.
 // Execute the command `rustlings hint intro1` for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     println!("Hello and");

exercises/intro/intro2.rs

@@ -2,8 +2,8 @@
 // Make the code print a greeting to the world.
 // Execute `rustlings hint intro2` for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    println!("Hello {}!");
+    let n = "World";
+    println!("Hello {}!", n);
 }

exercises/variables/variables1.rs

@@ -2,9 +2,10 @@
 // Make me compile!
 // Execute the command `rustlings hint variables1` if you want a hint :)
 
-// I AM NOT DONE
 
 fn main() {
-    x = 5;
+    let x = 5;
+    // When using string formating the value needs to be assigned before it can 
+    // be used, standard stuff.
     println!("x has the value {}", x);
 }

exercises/variables/variables2.rs

@@ -1,10 +1,9 @@
 // variables2.rs
 // Make me compile! Execute the command `rustlings hint variables2` if you want a hint :)
 
-// I AM NOT DONE
 
 fn main() {
-    let x;
+    let x = 1; // Orginally let x; Variables need defining from what I can tell.
     if x == 10 {
         println!("Ten!");
     } else {

exercises/variables/variables3.rs

@@ -1,10 +1,8 @@
 // variables3.rs
 // Make me compile! Execute the command `rustlings hint variables3` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
-    let x = 3;
+    let mut x = 5;
     println!("Number {}", x);
     x = 5; // don't change this line
     println!("Number {}", x);

exercises/variables/variables4.rs

@@ -1,9 +1,8 @@
 // variables4.rs
 // Make me compile! Execute the command `rustlings hint variables4` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
     let x: i32;
+    x = 6;
     println!("Number {}", x);
 }

exercises/variables/variables5.rs

@@ -1,11 +1,10 @@
 // variables5.rs
 // Make me compile! Execute the command `rustlings hint variables5` if you want a hint :)
 
-// I AM NOT DONE
-
 fn main() {
     let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
-    number = 3;
+    let number = 3; // if we want to reuse a varibale name we need to use
+                    // Shadowing, this is different from making a var mutable
     println!("Number plus two is : {}", number + 2);
 }

exercises/variables/variables6.rs

@@ -1,9 +1,7 @@
 // variables6.rs
 // Make me compile! Execute the command `rustlings hint variables6` if you want a hint :)
 
-// I AM NOT DONE
+const NUMBER: i32 = 3; // Consts need to be assigned a type
-
-const NUMBER = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }