Go程式設計語言允許傳遞一個指標到函式中。 為此,只需將函式的引數宣告為指標型別。
看看下面一個簡單的例子,傳遞了兩個指標給一個函式,並在函式裡面改變它們的值,這個值反映在呼叫函式中:
package main
import "fmt"
func main() {
/* local variable definition */
var a int = 100
var b int= 200
fmt.Printf("Before swap, value of a : %d\n", a )
fmt.Printf("Before swap, value of b : %d\n", b )
/* calling a function to swap the values.
* &a indicates pointer to a ie. address of variable a and
* &b indicates pointer to b ie. address of variable b.
*/
swap(&a, &b);
fmt.Printf("After swap, value of a : %d\n", a )
fmt.Printf("After swap, value of b : %d\n", b )
}
func swap(x *int, y *int) {
var temp int
temp = *x /* save the value at address x */
*x = *y /* put y into x */
*y = temp /* put temp into y */
}
當上述程式碼編譯和執行時,它產生以下結果:
Before swap, value of a :100
Before swap, value of b :200
After swap, value of a :200
After swap, value of b :100