Merge 6b2ceb59eb into 8d0aa11a35

exercises/09_strings/strings1.rs

@@ -5,7 +5,6 @@
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let answer = current_favorite_color();
@@ -13,5 +12,6 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    // "blue".to_string() // can be used to make strings from different types (aka integers, floats, chars, etc.)
+    String::from("blue") // can only be used to make strings from &string(string slices)
 }

exercises/09_strings/strings2.rs

@@ -5,11 +5,12 @@
 // Execute `rustlings hint strings2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let word = String::from("green"); // Try not changing this line :)
-    if is_a_color_word(word) {
+
+    // This needs to be a string slice because the function is expecting a string slice.
+    if is_a_color_word(&word) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");

exercises/09_strings/strings3.rs

@@ -3,21 +3,31 @@
 // Execute `rustlings hint strings3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn trim_me(input: &str) -> String {
     // TODO: Remove whitespace from both ends of a string!
-    ???
+    input.trim().to_string()
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+   
+    // let mut new_string = String::new();
+    // new_string.push_str(input);
+    // new_string.push_str(" world!");
+    // new_string
+
+    format!("{input} {}", "world!")
+
+    // let a = input.to_string();
+    // let b = " world!".to_string();
+    // a + &b
+
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    input.replace("cars", "balloons")
 }
 
 #[cfg(test)]

exercises/09_strings/strings4.rs

@@ -7,8 +7,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
-
 fn string_slice(arg: &str) {
     println!("{}", arg);
 }
@@ -17,14 +15,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ???("blue");
+    string_slice("blue");
-    ???("red".to_string());
+    string("red".to_string());
-    ???(String::from("hi"));
+    string(String::from("hi"));
-    ???("rust is fun!".to_owned());
+    string("rust is fun!".to_owned()); // this is cloning
-    ???("nice weather".into());
+    string_slice("nice weather".into()); // calls it self
-    ???(format!("Interpolation {}", "Station"));
+    string(format!("Interpolation {}", "Station"));
-    ???(&String::from("abc")[0..1]);
+    string_slice(&String::from("abc")[0..1]);
-    ???("  hello there ".trim());
+    string_slice("  hello there ".trim());
-    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }

exercises/10_modules/modules1.rs

@@ -3,15 +3,13 @@
 // Execute `rustlings hint modules1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 mod sausage_factory {
     // Don't let anybody outside of this module see this!
     fn get_secret_recipe() -> String {
         String::from("Ginger")
     }
 
-    fn make_sausage() {
+    pub fn make_sausage() {
         get_secret_recipe();
         println!("sausage!");
     }

exercises/10_modules/modules2.rs

@@ -7,12 +7,10 @@
 // Execute `rustlings hint modules2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 mod delicious_snacks {
     // TODO: Fix these use statements
-    use self::fruits::PEAR as ???
+    pub use self::fruits::PEAR as fruit;
-    use self::veggies::CUCUMBER as ???
+    pub use self::veggies::CUCUMBER as veggie;
 
     mod fruits {
         pub const PEAR: &'static str = "Pear";

exercises/10_modules/modules3.rs

@@ -8,10 +8,12 @@
 // Execute `rustlings hint modules3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 // TODO: Complete this use statement
-use ???
+// The * is a glob operator. It imports all public items from the module.
+// use std::time::*;
+
+// You can also write a nested path to specify the public items you want to pull in.
+use std::time::{SystemTime, UNIX_EPOCH};
 
 fn main() {
     match SystemTime::now().duration_since(UNIX_EPOCH) {

exercises/11_hashmaps/hashmaps1.rs

@@ -11,17 +11,18 @@
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::new();// TODO: declare your hash map here.
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
 
     // TODO: Put more fruits in your basket here.
+    basket.insert(String::from("apple"), 3);
+    basket.insert(String::from("pear"), 5);
 
     basket
 }

exercises/11_hashmaps/hashmaps2.rs

@@ -14,8 +14,6 @@
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 #[derive(Hash, PartialEq, Eq)]
@@ -40,6 +38,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Insert new fruits if they are not already present in the
         // basket. Note that you are not allowed to put any type of fruit that's
         // already present!
+        basket.entry(fruit).or_insert(1);
     }
 }
 

exercises/11_hashmaps/hashmaps3.rs

@@ -14,8 +14,6 @@
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 // A structure to store the goal details of a team.
@@ -30,6 +28,7 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
 
     for r in results.lines() {
         let v: Vec<&str> = r.split(',').collect();
+        println!("result { }", r);
         let team_1_name = v[0].to_string();
         let team_1_score: u8 = v[2].parse().unwrap();
         let team_2_name = v[1].to_string();
@@ -39,7 +38,23 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // will be the number of goals conceded by team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
-    }
+        let team_1 = scores.entry(team_1_name).or_insert(Team {
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+
+        team_1.goals_scored += team_1_score;
+        team_1.goals_conceded += team_2_score;
+
+       let team_2 = scores.entry(team_2_name).or_insert(Team {
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+
+        team_2.goals_scored += team_2_score;
+        team_2.goals_conceded += team_1_score;
+    };
+
     scores
 }
 

exercises/12_options/options1.rs

@@ -3,7 +3,6 @@
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
@@ -13,7 +12,13 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // value of 0 The Option output should gracefully handle cases where
     // time_of_day > 23.
     // TODO: Complete the function body - remember to return an Option!
-    ???
+    if time_of_day > 23 {
+        None
+    } else if time_of_day >= 22 {
+        Some(0)
+    } else {
+        Some(5)
+    }
 }
 
 #[cfg(test)]
@@ -34,6 +39,10 @@ mod tests {
         // TODO: Fix this test. How do you get at the value contained in the
         // Option?
         let icecreams = maybe_icecream(12);
-        assert_eq!(icecreams, 5);
+        assert_eq!(icecreams.unwrap(), 5);
     }
 }
+
+// Option has two variants: None and Some 
+// Some is a tuple struct that wraps a value with type T
+// None indicates failure or lack of value

exercises/12_options/options2.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
@@ -13,16 +11,21 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
+        // This block is checking whether or not optional_target is a typen  of Some(T)
+        // Since it is, it's binding the value of Some(target) to word. 
+
+        // The result is word = Some(Some(target))
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
-    }
+    } 
 
     #[test]
     fn layered_option() {
         let range = 10;
         let mut optional_integers: Vec<Option<i8>> = vec![None];
 
+        // Range is inclusive of the start and exclusive of the end. 
         for i in 1..(range + 1) {
             optional_integers.push(Some(i));
         }
@@ -32,7 +35,8 @@ mod tests {
         // TODO: make this a while let statement - remember that vector.pop also
         // adds another layer of Option<T>. You can stack `Option<T>`s into
         // while let and if let.
-        integer = optional_integers.pop() {
+       while let Some(Some(integer)) = optional_integers.pop() {
+            // Removes the last character for the vector and return it
             assert_eq!(integer, cursor);
             cursor -= 1;
         }

exercises/12_options/options3.rs

@@ -13,7 +13,8 @@ struct Point {
 fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
-    match y {
+    match y { // &y can also be used here to borrow instead of moving ownership of y to the match expression
+        // ref is used during pattern matching. 
         Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => panic!("no match!"),
     }

exercises/quiz2.rs

@@ -20,8 +20,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
-
 pub enum Command {
     Uppercase,
     Trim,
@@ -32,11 +30,24 @@ mod my_module {
     use super::Command;
 
     // TODO: Complete the function signature!
-    pub fn transformer(input: ???) -> ??? {
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
         // TODO: Complete the output declaration!
-        let mut output: ??? = vec![];
+        let mut output: Vec<String> = vec![];
         for (string, command) in input.iter() {
             // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Uppercase => output.push(string.to_uppercase()),
+                Command::Trim => output.push(string.trim().to_string()),
+                Command::Append(count) => {
+                    let mut new_string = string.clone();
+                    // The star in front of count dereferences the value of count. 
+                    // This is necessary because the append method expects a usize, not a &usize.
+                    for  _ in 0..*count {
+                        new_string.push_str("bar");
+                    }       
+                    output.push(new_string)
+                }
+            }
         }
         output
     }
@@ -45,7 +56,7 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we need to import to have `transformer` in scope?
-    use ???;
+    use crate::my_module::transformer;
     use super::Command;
 
     #[test]