Defer to Clean Up
Use defer to clean up resources such as files and locks.
| Bad | Good |
|---|---|
| ```go p.Lock() if p.count < 10 { p.Unlock() return p.count } p.count++ newCount := p.count p.Unlock() return newCount // easy to miss unlocks due to multiple returns ``` | ```go p.Lock() defer p.Unlock() if p.count < 10 { return p.count } p.count++ return p.count // more readable ``` |
Defer has an extremely small overhead and should be avoided only if you can
prove that your function execution time is in the order of nanoseconds. The
readability win of using defers is worth the miniscule cost of using them. This
is especially true for larger methods that have more than simple memory
accesses, where the other computations are more significant than the defer.