defer the execution order

package main

import (
	"fmt"
)

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

func main() {
	a := 1
	b := 2
	defer calc("1", a, calc("10", a, b))
	a = 0
	defer calc("2", a, calc("20", a, b))
	b = 1
}

/*
10 1 2 3
20 0 2 2
2 0 2 2
1 1 3 4
*/

Test sites: defer the execution order  answer: to note defer the execution order and deliver value index: 1 is definitely the last to perform, but the index: 1. The third parameter is a function, so the first is called calc ( "10", 1 2) ==> 10,1,2,3 execute index: 2, as before, we need to call the calc ( "20", 0,2) ==> 20,0,2,2 to execute b = 1 time to start calling, index: 2 ==> calc ( "2", 0,2) ==> 2,0,2,2 final performance index: 1 ==> calc ( " 1", 1,3) = => 1,1,3,4