loop 1

package main

func main() {
	x := []int{7, 8, 9}
	y := [3]*int{}
	for i, v := range x {
		defer func() {
			print(v)
		}()
		y[i] = &i
	}
	print(*y[0], *y[1], *y[2], " ")
}

• Prior to Go 1.22, the iteration variables (here they are i and v) are shared by all loop steps. In other words, each iteration variable only has one instance during the execution of the loop. That means all the elements of y store the same address (of the value v). In the end, the variable i is set as 2, and the variable v is set as 9.

• Since Go 1.22, the iteration variables (here they are i and v) will get new instances at each loop step. So, since Go 1.22, the output is 222 999.

package main

func main() {
	x := []int{7, 8, 9}
	y := [3]*int{}
	for i, v := range x {
		defer print(v)
		
		i := i
		y[i] = &i
	}
	print(*y[0], *y[1], *y[2], " ")
}