mlowicki

> go install github.com/mlowicki/lab && ./bin/lab
Before defer statement
After defer statement
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x549b3]

goroutine 1 [running]:
panic(0xda6c0, 0x8201c80e0)
        /usr/local/go/src/runtime/panic.go:481 +0x3e6
main.main()

mlowicki

package main

import "fmt"

func main() {
    f := func() {}
    f = nil
    fmt.Println("Before defer statement")
    defer f()
    fmt.Println("After defer statement")

mlowicki

package main

import "fmt"

type T struct{}

func (t T) m() {
    fmt.Println("Inside method")
}

mlowicki

> go install github.com/mlowicki/lab && ./bin/lab
3
2
1

mlowicki

package main

import "fmt"

func main() {
    defer func() {
        fmt.Println("1")
    }()
    defer func() {
        fmt.Println("2")

mlowicki

> go install github.com/mlowicki/lab && ./bin/lab
Inside f, n=1

mlowicki

package main

import "fmt"

func main() {
    f := func(n int) {
        fmt.Printf("Inside f, n=%d\n", n)
    }
    n := 1
    defer f(n)

mlowicki

> go install github.com/mlowicki/lab && ./bin/lab
1
2
Inside deferred function
panic: boom!

goroutine 1 [running]:
panic(0xb8260, 0x8202301f0)
        /usr/local/go/src/runtime/panic.go:481 +0x3e6
main.f()

mlowicki

package main

import "fmt"

func f() {
    fmt.Println("1")
    defer func() {
        fmt.Println("Inside deferred function")
    }()
    fmt.Println("2")

mlowicki

> go install github.com/mlowicki/lab && ./bin/lab
1
2
Inside deferred function