151 lines
2.1 KiB
Markdown
151 lines
2.1 KiB
Markdown
1.
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```rust
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fn main() {
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let x = String::from("hello, world");
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let y = x.clone();
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println!("{},{}",x,y);
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}
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```
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```rust
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fn main() {
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let x = "hello, world";
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let y = x;
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println!("{},{}",x,y);
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}
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```
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```rust
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fn main() {
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let x = &String::from("hello, world");
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let y = x;
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println!("{},{}",x,y);
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}
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```
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```rust
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fn main() {
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let x = 10;
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let y = x;
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println!("{},{}",x,y);
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}
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```
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2.
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```rust
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// Don't modify code in main!
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fn main() {
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let s1 = String::from("hello, world");
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let s2 = take_ownership(s1);
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println!("{}", s2);
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}
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// Only modify the code below!
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fn take_ownership(s: String) -> String {
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println!("{}", s);
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s
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}
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```
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3.
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```rust
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fn main() {
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let s = give_ownership();
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println!("{}", s);
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}
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// Only modify the code below!
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fn give_ownership() -> String {
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let s = String::from("hello, world");
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// convert String to Vec
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let _s = s.as_bytes();
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s
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}
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```
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```rust
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fn main() {
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let s = give_ownership();
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println!("{}", s);
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}
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// Only modify the code below!
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fn give_ownership() -> String {
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let s = String::from("hello, world");
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s
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}
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```
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4.
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```rust
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fn main() {
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let s = String::from("hello, world");
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print_str(s.clone());
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println!("{}", s);
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}
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fn print_str(s: String) {
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println!("{}",s)
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}
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```
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5.
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```rust
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fn main() {
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let x = (1, 2, (), "hello");
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let y = x;
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println!("{:?}, {:?}", x, y);
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}
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```
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6.
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```rust
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fn main() {
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let s = String::from("hello, ");
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// modify this line only !
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let mut s1 = s;
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s1.push_str("world")
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}
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```
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7.
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```rust
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fn main() {
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let x = Box::new(5);
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let mut y = Box::new(3); // implement this line, dont change other lines!
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*y = 4;
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assert_eq!(*x, 5);
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}
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```
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8.
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```rust
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fn main() {
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let t = (String::from("hello"), String::from("world"));
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let _s = t.0;
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// modify this line only, don't use `_s`
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println!("{:?}", t.1);
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}
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```
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9.
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```rust
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fn main() {
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let t = (String::from("hello"), String::from("world"));
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// fill the blanks
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let (s1, s2) = t.clone();
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println!("{:?}, {:?}, {:?}", s1, s2, t); // -> "hello", "world", ("hello", "world")
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}
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``` |