> For the complete documentation index, see [llms.txt](https://cracker8090.gitbook.io/rustnotes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cracker8090.gitbook.io/rustnotes/rust-jin-jie/suo-you-quan/qie-pian.md).

# 切片

\&str

字符串切片的边界必须位于有效的UTF-8字符边界内

```rust
fn first_world_slice(s: &str) -> &str {
    let bytes = s.as_bytes();

    for (i, &item) in bytes.iter().enumerate() {
        if item == b' ' {
            return &s[..i];
        }
    }
    &s[..]
}

    let my_string = String::from("Hello world");
    let word_index = first_world_slice(&my_string);

    let my_string_literal = "hello world";
    let word_index = first_world_slice(my_string_literal);
```


---

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