Ownership

Additional Resources

Exercises

Moving on assignment

// Something's missing. Fix the code so that it compiles.

fn main() {
    let s1 = String::from("Rust");
    let mut s2 = s1;
    s2.push_str(" is an awesome language");
    println!("String:\"{s1}\" is a substring of \"{s2}\"");
}
Solution 
fn main() {
  let s1 = String::from("Rust");
  let mut s2 = s1.clone();
  s2.push_str(" is an awesome language");
  println!("String:\"{s1}\" is a substring of \"{s2}\"");
}

Moving on assignment 2

// Fix the code so that it compiles. Modify only one statement.

fn main() {
    let mut my_str = String::from("Example");
    let mut temp;
    while my_str.len() > 0 {
        temp = my_str;
        println!("Length of temporary string is: {}", temp.len());
        my_str.pop();
    }
}
Solution
Description

The ownership of a value is assigned upon the assignment of the value itself. We need to be aware of the ownership of a value every time an assignment of a value occurs.

fn main() {
  let mut my_str = String::from("Example");
  let mut temp;
  while my_str.len() > 0 {
      temp = my_str.clone();
      println!("Length of temporary string is: {}", temp.len());
      my_str.pop();
  }
}

Moving into function

// Fix the code so that it compiles.

fn main() {
    let my_string = String::from("I love rust bootcamp 💕");
    let occurence_count = count_occurences(my_string, 'o');
    println!("The number of times 'o' apprears in \"{my_string}\" = {occurence_count}");
}

// this function counts the number of times a letter appears in a text
fn count_occurences(text: String, letter: char) -> u32 {
    let mut res = 0;
    for ch in text.chars() {
        if ch == letter {
            res += 1;
        }
    }
    res
}
Solution 
fn main() {
  let my_string = String::from("I love rust bootcamp 💕");
  let occurence_count = count_occurences(&my_string, 'o');
  println!("The number of times 'o' apprears in \"{my_string}\" = {occurence_count}");
  }

  // this function counts the number of times a letter appears in a text
fn count_occurences(text: &String, letter: char) -> u32 {
  let mut res = 0;
  for ch in text.chars() {
      if ch == letter {
          res += 1;
      }
  }
  res
}

Moving out of function

// Make the following code compile by modifying only one statement.

fn main() {
    let mut str1 = get_new_string();
    println!("Printing through str1: {}", str1);
    let mut str2 = str1;
    println!("Printing through str2: {}", str2);
    str1 = str2;
    println!("Again printing through str1: {}", str1);
    str2 = str1;
    println!("Again printing through str2: {}", str2);
    println!("Printing thourgh both: {}, {}", str1, str2);
}

fn get_new_string() -> String {
    let new_string = String::from("I will master rust 🦀 🦀");
    new_string
} // string ownership is transferred to the calling function
Solution 
fn main() {
  let mut str1 = get_new_string();
  println!("Printing through str1: {}", str1);
  let mut str2 = str1;
  println!("Printing through str2: {}", str2);
  str1 = str2;
  println!("Again printing through str1: {}", str1);
  str2 = str1.clone();
  println!("Again printing through str2: {}", str2);
  println!("Printing thourgh both: {}, {}", str1, str2);
}

fn get_new_string() -> String {
  let new_string = String::from("I will master rust 🦀 🦀");
  new_string
} // string ownership is transferred to the calling function