94 lines
1.6 KiB
Markdown
94 lines
1.6 KiB
Markdown
# 函数
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1. 🌟🌟🌟
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```rust,editable
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fn main() {
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// 不要修改下面两行代码!
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let (x, y) = (1, 2);
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let s = sum(x, y);
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assert_eq!(s, 3);
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}
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fn sum(x, y: i32) {
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x + y;
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}
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```
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2. 🌟🌟
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```rust,editable
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fn main() {
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print();
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}
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// 使用另一个类型来替代 i32
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fn print() -> i32 {
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println!("hello,world");
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}
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```
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3. 🌟🌟🌟
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```rust,editable
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// 用两种方法求解
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fn main() {
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never_return();
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}
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fn never_return() -> ! {
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// 实现这个函数，不要修改函数签名!
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}
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```
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4. 🌟🌟 发散函数( Diverging function )不会返回任何值，因此它们可以用于替代需要返回任何值的地方
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```rust,editable
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fn main() {
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println!("Success!");
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}
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fn get_option(tp: u8) -> Option<i32> {
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match tp {
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1 => {
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// TODO
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}
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_ => {
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// TODO
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}
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};
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// 这里与其返回一个 None，不如使用发散函数替代
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never_return_fn()
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}
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// 使用三种方法实现以下发散函数
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fn never_return_fn() -> ! {
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}
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```
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5. 🌟🌟
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```rust,editable
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fn main() {
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// 填空
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let b = __;
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let _v = match b {
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true => 1,
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// 发散函数也可以用于 `match` 表达式，用于替代任何类型的值
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false => {
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println!("Success!");
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panic!("we have no value for `false`, but we can panic")
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}
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};
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println!("Exercise Failed if printing out this line!");
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}
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```
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> 你可以在[这里](https://github.com/sunface/rust-by-practice/blob/master/solutions/basic-types/functions.md)找到答案(在 solutions 路径下)
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