# 误用字符串

当需要对一个字符串进行频繁的操作时，谨记在go语言中字符串是不可变的（类似java和c#）。使用诸如`a += b`形式连接字符串效率低下，尤其在一个循环内部使用这种形式。这会导致大量的内存开销和拷贝。**应该使用一个字符数组代替字符串，将字符串内容写入一个缓存中。** 例如以下的代码示例：

```go
var b bytes.Buffer
...
for condition {
    b.WriteString(str) // 将字符串str写入缓存buffer
}
    return b.String()
```

注意：由于编译优化和依赖于使用缓存操作的字符串大小，当循环次数大于15时，效率才会更佳。

## 链接

* [目录](https://github.com/yangchuansheng/the-way-to-go_ZH_CN/tree/f30ab7d8c58f85840a0afb548024b93642b518d5/eBook/directory.md)
* 上一节：[误用短声明导致变量覆盖](/the-way-to-go-zh-cn/di-si-bu-fen-shi-ji-ying-yong/16.0/16.1.md)
* 下一节：[发生错误时使用defer关闭一个文件](/the-way-to-go-zh-cn/di-si-bu-fen-shi-ji-ying-yong/16.0/16.3.md)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ryanyang.gitbook.io/the-way-to-go-zh-cn/di-si-bu-fen-shi-ji-ying-yong/16.0/16.2.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.