snapshot of https://github.com/uber-go/guide.git (master, 2026-09-15; blobs > 131072B omitted)

src/defer-clean.md

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+# Defer to Clean Up
+
+Use defer to clean up resources such as files and locks.
+
+<table>
+<thead><tr><th>Bad</th><th>Good</th></tr></thead>
+<tbody>
+<tr><td>
+
+```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
+```
+
+</td><td>
+
+```go
+p.Lock()
+defer p.Unlock()
+
+if p.count < 10 {
+  return p.count
+}
+
+p.count++
+return p.count
+
+// more readable
+```
+
+</td></tr>
+</tbody></table>
+
+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`.