Go编程语言允许传递一个指针到函数中。 为此,只需将函数的参数声明为指针类型。看看下面一个简单的例子,传递了两个指针给一个函数,并在函数里面改变它们的值,这个值反映在调用函数中:
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 */ }
当上述代码编译和执行时,它产生以下结果:
Before swap, value of a :100 Before swap, value of b :200 After swap, value of a :200 After swap, value of b :100