65 lines
1.0 KiB
Markdown
65 lines
1.0 KiB
Markdown
# 语句与表达式
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### 示例
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```rust,editable
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fn main() {
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let x = 5u32;
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let y = {
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let x_squared = x * x;
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let x_cube = x_squared * x;
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// 下面表达式的值将被赋给 `y`
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x_cube + x_squared + x
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};
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let z = {
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// 分号让表达式变成了语句，因此返回的不再是表达式 `2 * x` 的值，而是语句的值 `()`
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2 * x;
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};
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println!("x is {:?}", x);
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println!("y is {:?}", y);
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println!("z is {:?}", z);
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}
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```
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### 练习
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1. 🌟🌟
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```rust,editable
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// 使用两种方法让代码工作起来
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fn main() {
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let v = {
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let mut x = 1;
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x += 2
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};
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assert_eq!(v, 3);
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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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let v = (let x = 3);
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assert!(v == 3);
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}
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```
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3. 🌟
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```rust,editable
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fn main() {
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let s = sum(1 , 2);
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assert_eq!(s, 3);
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}
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fn sum(x: i32, y: i32) -> i32 {
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x + y;
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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/statements.md)找到答案(在 solutions 路径下)
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