Go 传递指针给函数

Go编程语言允许你将指针传递给函数。要做到这一点，只需将函数参数声明为指针类型。

在下面的示例中，我们传递了两个指针给一个函数，并在函数内部改变了值，这个改变反映在调用函数中。

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 */
}

当以上代码被编译和执行时，将产生以下结果-

Before swap, value of a :100
Before swap, value of b :200
After swap, value of a :200
After swap, value of b :100