package main
func bar() (r int) {
defer func() {
r += 4
if recover() != nil {
r += 8
}
}()
var f func()
defer f()
f = func() {
r += 2
}
return 1
}
func main() {
println(bar())
}
Choices:
Answer: 13
Run it on Go play.
Key points:
f() is pushed to the defer call queue,
f is evaluated as nil. Calling a nil function produces a panic.
But the panic doesn't happen at the push time.
Instead, it will panic at the execution time later during the exiting phase of the bar() call.
f has not any impacts on the execution effect.
In other words, this assignment is actually a no-op.
bar function).
The Go 101 project is hosted on Github. Welcome to improve Go 101 articles by submitting corrections for all kinds of mistakes, such as typos, grammar errors, wording inaccuracies, description flaws, code bugs and broken links.
If you would like to learn some Go details and facts every serveral days, please follow Go 101's official Twitter account @zigo_101.