package main
import "fmt"
type Item struct {
val int
}
func main() {
var items []*Item
item := Item{}
items = append(items, &item)
x := items[0]
y := *x
x.val++
fmt.Printf("x=%v, y=%v\n", *x, y)
}
This prints:
x={1}, y={0}
I can’t understand why the values are different. x is a pointer to the 1st element in the array, and we increment the val field using x, then the 1st element has been changed. y is the first element, and its val should’ve changed too, but didn’t? If, however, the y := *x statement is moved to after x.val++, then the values are equal. Why?
>Solution :
Only this line needs to be explained
y := *x
and it means to take value from this pointer (*x) and assign it to y, now y has a freshly non connected to x value.