Feat: Add shadowing, borrowing and ownership works

src/day04_to_day06/borrowing.rs

@@ -0,0 +1,32 @@
+pub fn run() {
+    let mut book = String::from("The Rust Programming Language");
+
+    read_book(&book); 
+
+    annotate_book(&mut book, " - What a nice book!"); 
+
+    read_book(&book); 
+
+    println!("I am still got a book: {}", book);
+    }
+
+    fn read_book(book: &String) {
+        println!("Reading: {}", book);
+    }
+
+    fn annotate_book(book: &mut String, note: &str) {
+        book.push_str(note);
+        println!("Added annotate to book");
+    }
+
+
+    /*
+    Output:
+    Đang đọc: The Rust Programming Language
+    Đã add ghi chú vào book
+    Đang đọc: The Rust Programming Language - Sách hay!
+    Tôi vẫn sở hữu book: The Rust Programming Language - Sách hay!
+    */
+    /*
+    book.push_str(note); thay đổi nội dung của book.
+    */

src/day04_to_day06/mod.rs

@@ -0,0 +1,3 @@
+pub mod shadowing;
+pub mod ownership;
+pub mod borrowing;

src/day04_to_day06/ownership.rs

@@ -0,0 +1,10 @@
+//ownership works
+
+    pub fn run() {
+        let my_banhmi = String::from("bánh mì");
+        eat_pizza(my_banhmi); 
+        }
+
+    fn eat_pizza(banhmi: String) {
+        println!("I am eating {}!", banhmi);
+    }

src/day04_to_day06/shadowing.rs

@@ -0,0 +1,13 @@
+pub fn run(){
+    //Init a variable
+    let x = 5;
+    let x = x * 2;
+    println!("x = {}", x);
+    /*
+    In this example, let x = 5; initializes x with the value 5. Then, let x = x * 2; creates a new variable also named x, which "shadows" the original x. This isn't modifying the original x (that would be mutability), but rather creating a completely new variable with the same name. The new x has a value of 10 (5 * 2). 
+    */
+
+    /*Key point:
+    Shadowing is a useful tool in Rust, allowing you to reuse variable names without losing the immutability of the original variables and offering flexible transformation in terms of data types.
+     */
+}

src/main.rs

@@ -0,0 +1,50 @@
+//Day 01 to day03
+pub mod day01_to_day03;
+
+// use day01_to_day03::print;
+// use day01_to_day03::strings;
+// use day01_to_day03::functions;
+// use day01_to_day03::types;
+// use day01_to_day03::arrays;
+// use day01_to_day03::vars;
+// use day01_to_day03::cli;
+// use day01_to_day03::loops;
+// use day01_to_day03::vectors;
+// use day01_to_day03::structs;
+// use day01_to_day03::conditionals;
+// use day01_to_day03::enums;
+// use day01_to_day03::pointer_ref;
+
+//Day04 to day06
+pub mod day04_to_day06;
+use day04_to_day06::shadowing;
+use day04_to_day06::ownership;
+use day04_to_day06::borrowing;
+
+
+fn main() {
+    //Hello world in rust
+    // println!("Hello, world!");
+    //Day 01 to day03
+
+    // //Print from an another file!
+    // print::run();
+    // strings::run();
+    // functions::run();
+    // types::run();
+    // arrays::run();
+    // vars::run();
+    // cli::run();
+    // loops::run();
+    // vectors::run();
+    // structs::run();
+    // conditionals::run();
+    // enums::run();
+    // pointer_ref::run();
+
+    //Day04 to day06
+    // shadowing::run();
+    // ownership::run();
+    borrowing::run();
+
+}