defer func (parameter) {}

defer func (parameter) {}

• Reference Code

func main(){
    fmt.Println("================打印顺序===============")
    a:=1
    b:=2
    defer calc("1",a,calc("10",a,b))
    a=0
    defer calc("2",a,calc("20",a,b))
    b=1
    fmt.Println("a=",a,"b=",b)
}

func calc(index string, a,b int)int{
    ret := a+b
    fmt.Println(index,a,b,ret)
    return ret
}

• Output

================打印顺序===============
10 1 2 3
20 0 2 2
a= 0 b= 1
2 0 2 2
1 1 3 4

• Result analysis
  • defer operating characteristics
    • Executed after return
    • After the first assignment on the stack