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5 Gotchas of Defer in Go (Golang) — Part I
#1 — Deferred nil funcIf a deferred func evaluates to nil, execution panics when the surrounding func ends, not when defer is called. Examplefunc() { var run func() = nil defer run() fmt.Println("runs") }Outputruns❗️ panic: runtime error: invalid memory address or nil pointer dereferenceWhy?Here, the func continues until the end, after that the deferred func will run and panic because it’s nil. Ho
ikosin 2017/12/22
go
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Go Defer Simplified with Practical Visuals
What is defer?It takes a func and executes it just before* the surrounding func returns whether there is a panic or not. 👉 Go doesn’t need destructors because it has no built-in constructors. This is a good balance. 👉 Defer resem bles to “finally” however the defer belongs to the surrounding “func” while the finally belongs to an exception “block”. 👊 Bonus: See my comment here about the internal
ikosin 2017/12/22
go
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