rust-by-practice/en/src/ownership/ownership.md

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# Ownership
1. 🌟🌟
```rust,editable
fn main() {
// Use as many approaches as you can to make it work
let x = String::from("hello, world");
let y = x;
println!("{},{}",x,y);
}
```
2. 🌟🌟
```rust,editable
// Don't modify code in main!
fn main() {
let s1 = String::from("hello, world");
let s2 = take_ownership(s1);
println!("{}", s2);
}
// Only modify the code below!
fn take_ownership(s: String) {
println!("{}", s);
}
```
3. 🌟🌟
```rust,editable
fn main() {
let s = give_ownership();
println!("{}", s);
}
// Only modify the code below!
fn give_ownership() -> String {
let s = String::from("hello, world");
// Convert String to Vec
let _s = s.into_bytes();
s
}
```
4. 🌟🌟
```rust,editable
// Fix the error without removing code line
fn main() {
let s = String::from("hello, world");
print_str(s);
println!("{}", s);
}
fn print_str(s: String) {
println!("{}",s)
}
```
5. 🌟🌟
```rust,editable
// Don't use clone ,use copy instead
fn main() {
let x = (1, 2, (), "hello".to_string());
let y = x.clone();
println!("{:?}, {:?}", x, y);
}
```
#### Mutability
Mutability can be changed when ownership is transferred.
6. 🌟
```rust,editable
fn main() {
let s = String::from("hello, ");
// Modify this line only !
let s1 = s;
s1.push_str("world");
println!("Success!");
}
```
7. 🌟🌟🌟
```rust,editable
fn main() {
let x = Box::new(5);
let ... // Implement this line, dont change other lines!
*y = 4;
assert_eq!(*x, 5);
println!("Success!");
}
```
### Partial move
Within the destructuring of a single variable, both by-move and by-reference pattern bindings can be used at the same time. Doing this will result in a partial move of the variable, which means that parts of the variable will be moved while other parts stay. In such a case, the parent variable cannot be used afterwards as a whole, however the parts that are only referenced (and not moved) can still be used.
#### Example
```rust,editable
fn main() {
#[derive(Debug)]
struct Person {
name: String,
age: Box<u8>,
}
let person = Person {
name: String::from("Alice"),
age: Box::new(20),
};
// `name` is moved out of person, but `age` is referenced
let Person { name, ref age } = person;
println!("The person's age is {}", age);
println!("The person's name is {}", name);
// Error! borrow of partially moved value: `person` partial move occurs
//println!("The person struct is {:?}", person);
// `person` cannot be used but `person.age` can be used as it is not moved
println!("The person's age from person struct is {}", person.age);
}
```
#### Exercises
8. 🌟
```rust,editable
fn main() {
let t = (String::from("hello"), String::from("world"));
let _s = t.0;
// Modify this line only, don't use `_s`
println!("{:?}", t);
}
```
9. 🌟🌟
```rust,editable
fn main() {
let t = (String::from("hello"), String::from("world"));
// Fill the blanks
let (__, __) = __;
println!("{:?}, {:?}, {:?}", s1, s2, t); // -> "hello", "world", ("hello", "world")
}
```
> You can find the solutions [here](https://github.com/sunface/rust-by-practice)(under the solutions path), but only use it when you need it