1
f, err := os.Open("file.txt")
2
if err != nil {
3
    log.Fatal(err)
4
}
5
defer f.Close() // 函数返回前自动关闭文件

1
mu.Lock()
2
defer mu.Unlock() // 忘记解锁或提前 return 也不会死锁

1
defer func() {
2
    if r := recover(); r != nil {
3
        fmt.Println("恢复 panic:", r)
4
    }
5
}()

1
func foo() {
2
    start := time.Now()
3
    defer func() { fmt.Println("耗时:", time.Since(start)) }()
4
    // ...
5
}

1
resp, err := http.Get(url)
2
if err != nil {
3
    return err
4
}
5
defer resp.Body.Close()