你如何逐个字符地遍历一个字符串 [英] How do you iterate over a string by character

问题描述

我有一个字符串，我需要扫描每次出现的foo"并读取它后面的所有文本，直到第二个 ".因为 Rust 没有 包含字符串函数，我需要通过字符扫描来迭代它.我该怎么做?

I have a string and I need to scan for every occurrence of "foo" and read all the text following it until a second ". Since Rust does not have a contains function for strings, I need to iterate by characters scanning for it. How would I do this?

编辑:Rust 的 &str 有一个 contains() 和 find() 方法.

Edit: Rust's &str has a contains() and find() method.

推荐答案

我需要通过字符扫描来迭代它.

I need to iterate by characters scanning for it.

.chars() 方法返回字符串中字符的迭代器.例如

The .chars() method returns an iterator over characters in a string. e.g.

for c in my_str.chars() { 
    // do something with `c`
}

for (i, c) in my_str.chars().enumerate() {
    // do something with character `c` and index `i`
}

如果你对每个char的字节偏移量感兴趣，可以使用char_indices.

If you are interested in the byte offsets of each char, you can use char_indices.

查看 .peekable()，并使用 peek() 进行查看.之所以这样包装，是因为它支持 UTF-8 代码点，而不是简单的字符向量.

Look into .peekable(), and use peek() for looking ahead. It's wrapped like this because it supports UTF-8 codepoints instead of being a simple vector of characters.

您也可以创建一个 char 向量并从那里开始处理它，但这需要更多的时间和空间:

You could also create a vector of chars and work on it from there, but that's more time and space intensive:

let my_chars: Vec<_> = mystr.chars().collect();

这篇关于你如何逐个字符地遍历一个字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！