> For the complete documentation index, see [llms.txt](https://ryanyang.gitbook.io/the-way-to-go-zh-cn/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ryanyang.gitbook.io/the-way-to-go-zh-cn/di-san-bu-fen-go-gao-ji-bian-cheng/12.0/12.7.md).

# 用 defer 关闭文件

`defer` 关键字（参看 6.4）对于在函数结束时关闭打开的文件非常有用，例如下面的代码片段：

```go
func data(name string) string {
    f, _ := os.OpenFile(name, os.O_RDONLY, 0)
    defer f.Close() // idiomatic Go code!
    contents, _ := ioutil.ReadAll(f)
    return string(contents)
}
```

在函数 return 后执行了 `f.Close()`

## 链接

* [目录](https://github.com/yangchuansheng/the-way-to-go_ZH_CN/tree/f30ab7d8c58f85840a0afb548024b93642b518d5/eBook/directory.md)
* 上一节：[用切片读写文件](/the-way-to-go-zh-cn/di-san-bu-fen-go-gao-ji-bian-cheng/12.0/12.6.md)
* 下一节：[使用接口的实际例子：fmt.Fprintf](/the-way-to-go-zh-cn/di-san-bu-fen-go-gao-ji-bian-cheng/12.0/12.8.md)