Skip to content

修改G_EXP_05 关于自增和自减操作的表述 #39

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ZhangHanDong merged 2 commits into from
Nov 29, 2021
Merged

修改G_EXP_05 关于自增和自减操作的表述 #39

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
4d83c79
修改G_EXP_05 关于自增和自减操作的表述
surechen Nov 27, 2021
74d3498
edit
surechen Nov 27, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions src/safe-guides/coding_practice/expr.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -154,7 +154,7 @@ impl TagNumber {

```

## G.EXP.05 使用 `+=`/`-=` 等操作来代替 `++i` / `--i`
## G.EXP.05 自增/自减运算使用 `+=`/`-=`

### 【级别：建议】

Expand All @@ -168,20 +168,20 @@ impl TagNumber {

### 【描述】

`++i` 这种操作编译会失败，但是 `--i` 编译不会出错。有些C/Cpp等其他语言新手容易犯此错误。
C/Cpp 等编程语言常用的自增自减操作，如 `++i` 、`i++` 、`i--` 等不是合法的 Rust 表达式， `--i` 虽然是合法的 Rust 表达式，但是表达对i取反两次，而不是自减语义。

【正例】

```rust
let mut x = 3;
x -= 1;
x -= 1; // x == 2
```

【反例】

```rust
let mut x = 3;
--x;
--x; // x == 3
```

## G.EXP.06 表达式操作最好使用括号来表达清楚优先级顺序
Expand Down