Merge pull request #3 from ZhiHanZ/exercise_ans

string, primitive type, struct

exercises/primitive_types/primitive_types1.rs

@@ -2,7 +2,6 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Booleans (`bool`)
@@ -12,7 +11,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = false;// Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }

exercises/primitive_types/primitive_types2.rs

@@ -2,7 +2,6 @@
 // Fill in the rest of the line that has code missing!
 // No hints, there's no tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Characters (`char`)
@@ -16,7 +15,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '3';// Finish this line like the example! What's your favorite character?
     // Try a letter, try a number, try a special character, try a character
     // from a different language than your own, try an emoji!
     if your_character.is_alphabetic() {

exercises/primitive_types/primitive_types3.rs

@@ -2,10 +2,9 @@
 // Create an array with at least 100 elements in it where the ??? is. 
 // Execute `rustlings hint primitive_types3` for hints!
 
-// I AM NOT DONE
 
 fn main() {
-    let a = ???
+    let a = [1;100]; // 100 elem with 1
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/primitive_types/primitive_types4.rs

@@ -2,13 +2,13 @@
 // Get a slice out of Array a where the ??? is so that the test passes.
 // Execute `rustlings hint primitive_types4` for hints!!
 
-// I AM NOT DONE
 
 #[test]
 fn slice_out_of_array() {
     let a = [1, 2, 3, 4, 5];
 
-    let nice_slice = ???
-
-    assert_eq!([2, 3, 4], nice_slice)
+    let nice_slice = &a[1..a.len() - 1];
+//https://doc.rust-lang.org/book/ch15-02-deref.html
+// implement a deref trait 
+    assert_eq!([2, 3, 4], *nice_slice)
 }

exercises/primitive_types/primitive_types5.rs

@@ -2,11 +2,10 @@
 // Destructure the `cat` tuple so that the println will work.
 // Execute `rustlings hint primitive_types5` for hints!
 
-// I AM NOT DONE
 
 fn main() {
     let cat = ("Furry McFurson", 3.5);
-    let /* your pattern here */ = cat;
+    let (name, age) = cat; // tuple decoupling?
 
     println!("{} is {} years old.", name, age);
 }

exercises/primitive_types/primitive_types6.rs

@@ -3,9 +3,8 @@
 // You can put this right into the `println!` where the ??? is.
 // Execute `rustlings hint primitive_types6` for hints!
 
-// I AM NOT DONE
 
 fn main() {
     let numbers = (1, 2, 3);
-    println!("The second number is {}", ???);
+    println!("The second number is {}", numbers.2);
 }

exercises/strings/strings1.rs

@@ -2,13 +2,11 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings1` for hints ;)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = current_favorite_color();
     println!("My current favorite color is {}", answer);
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }

exercises/strings/strings2.rs

@@ -2,11 +2,10 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings2` for hints :)
 
-// I AM NOT DONE
 
 fn main() {
     let word = String::from("green"); // Try not changing this line :)
-    if is_a_color_word(word) {
+    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/structs/structs1.rs

@@ -1,13 +1,13 @@
 // structs1.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
 
-struct ColorClassicStruct {
-    // TODO: Something goes here
+struct ColorClassicStruct<'a> {
+    name: &'a str,
+    hex: &'a str,
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct<'a>(&'a str, &'a str);
 
 #[derive(Debug)]
 struct UnitStruct;
@@ -18,8 +18,7 @@ mod tests {
 
     #[test]
     fn classic_c_structs() {
-        // TODO: Instantiate a classic c struct!
-        // let green =
+        let green = ColorClassicStruct{name: "green", hex: "#00FF00"};
 
         assert_eq!(green.name, "green");
         assert_eq!(green.hex, "#00FF00");
@@ -27,8 +26,7 @@ mod tests {
 
     #[test]
     fn tuple_structs() {
-        // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = ColorTupleStruct("green", "#00FF00");
 
         assert_eq!(green.0, "green");
         assert_eq!(green.1, "#00FF00");
@@ -36,8 +34,7 @@ mod tests {
 
     #[test]
     fn unit_structs() {
-        // TODO: Instantiate a unit struct!
-        // let unit_struct =
+        let unit_struct = UnitStruct{};
         let message = format!("{:?}s are fun!", unit_struct);
 
         assert_eq!(message, "UnitStructs are fun!");

exercises/structs/structs2.rs

@@ -2,7 +2,6 @@
 // Address all the TODOs to make the tests pass!
 // No hints, just do it!
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 struct Order {
@@ -34,8 +33,7 @@ mod tests {
     #[test]
     fn your_order() {
         let order_template = create_order_template();
-        // TODO: Create your own order using the update syntax and template above!
-        // let your_order =
+        let your_order = Order{name: "Hacker in Rust".to_string(), count : 1, ..order_template};
         assert_eq!(your_order.name, "Hacker in Rust");
         assert_eq!(your_order.year, order_template.year);
         assert_eq!(your_order.made_by_phone, order_template.made_by_phone);

exercises/test2.rs

@@ -7,7 +7,6 @@
 // you think each value is. That is, add either `string_slice` or `string`
 // before the parentheses on each line. If you're right, it will compile!
 
-// I AM NOT DONE
 
 fn string_slice(arg: &str) {
     println!("{}", arg);
@@ -17,14 +16,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ("blue");
-    ("red".to_string());
-    (String::from("hi"));
-    ("rust is fun!".to_owned());
-    ("nice weather".into());
-    (format!("Interpolation {}", "Station"));
-    (&String::from("abc")[0..1]);
-    ("  hello there ".trim());
-    ("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string_slice("blue");
+    string("red".to_string());
+    string(String::from("hi"));
+    string("rust is fun!".to_owned()); //https://doc.rust-lang.org/std/borrow/trait.ToOwned.html
+    string("nice weather".into());
+    string(format!("Interpolation {}", "Station")); //format Marco println String type https://doc.rust-lang.org/std/fmt/
+    string_slice(&String::from("abc")[0..1]);
+    string_slice("  hello there ".trim());
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase()); //change thevalue and it will create a new String https://doc.rust-lang.org/std/primitive.str.html#method.to_lowercase
 }