What is the meaning of '*' and '&'?

Question

I am doing the http://tour.golang.org/. Could anyone explain me lines 1,3,5 and 7 this function especially what \'*\' and \'&\' do? I mean by mentioning the

Answer 1

This is by far the easiest way to understand all the three cases as explained in the @Everett answer

func zero(x int) {
  x = 0
}
func main() {
  x := 5
  zero(x)
  fmt.Println(x) // x is still 5
}

If you need a variable to be changed inside a function then pass the memory address as a parmeter and use the pointer of this memory address to change the variable permanently.

Observe the use of * in front of int in the example. Here it just represents the variable that is passed as a parameter is the address of type int.

func zero(xPtr *int) {
  *xPtr = 0
}
func main() {
  x := 5
  zero(&x)
  fmt.Println(x) // x is 0
}