2022-03-02 08:04:00 -06:00
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1.
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```rust
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fn main() {}
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fn match_number(n: i32) {
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match n {
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// match a single value
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1 => println!("One!"),
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// fill in the blank with `|`, DON'T use `..` ofr `..=`
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2 | 3 | 4 | 5 => println!("match 2 -> 5"),
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// match an inclusive range
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6..=10 => {
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println!("match 6 -> 10")
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},
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_ => {
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println!("match 11 -> +infinite")
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}
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}
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}
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```
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2.
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```rust
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struct Point {
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x: i32,
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y: i32,
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}
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fn main() {
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// fill in the blank to let p match the second arm
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let p = Point { x: 2, y: 20 }; // x can be [0, 5], y can be 10 20 or 30
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match p {
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Point { x, y: 0 } => println!("On the x axis at {}", x),
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// second arm
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Point { x: 0..=5, y: y@ (10 | 20 | 30) } => println!("On the y axis at {}", y),
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Point { x, y } => println!("On neither axis: ({}, {})", x, y),
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}
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}
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```
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3.
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```rust
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enum Message {
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Hello { id: i32 },
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}
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fn main() {
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let msg = Message::Hello { id: 5 };
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match msg {
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Message::Hello {
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id: id@3..=7,
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} => println!("Found an id in range [3, 7]: {}", id),
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Message::Hello { id: newid@(10 | 11 | 12) } => {
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println!("Found an id in another range [10, 12]: {}", newid)
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}
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Message::Hello { id } => println!("Found some other id: {}", id),
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}
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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 num = Some(4);
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let split = 5;
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match num {
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Some(x) if x < split => assert!(x < split),
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Some(x) => assert!(x >= split),
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None => (),
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}
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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 numbers = (2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048);
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match numbers {
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(first,..,last) => {
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assert_eq!(first, 2);
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assert_eq!(last, 2048);
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}
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}
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}
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2022-03-11 01:45:03 -06:00
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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 mut v = String::from("hello,");
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let r = &mut v;
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match r {
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// The type of value is &mut String
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value => value.push_str(" world!")
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}
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}
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2022-03-02 08:04:00 -06:00
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```
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