go实例之函数

1、可变参数

　　示例代码如下：

 package main

 import "fmt"

 // Here's a function that will take an arbitrary number
 // of `ints` as arguments.
 func sum(nums ...int) {
     fmt.Print(nums, " ")
     total :=
     for _, num := range nums {
         total += num
     }
     fmt.Println(total)
 }

 func main() {

     // Variadic functions can be called in the usual way
     // with individual arguments.
     sum(, )
     sum(, , )

     // If you already have multiple args in a slice,
     // apply them to a variadic function using
     // `func(slice...)` like this.
     nums := []int{, , , }
     sum(nums...)
 }

　　执行上面代码，将得到以下输出结果

 [ ]
 [  ]
 [   ] 

2、匿名函数

　　示例代码如下：

 package main

 import "fmt"

 // This function `intSeq` returns another function, which
 // we define anonymously in the body of `intSeq`. The
 // returned function _closes over_ the variable `i` to
 // form a closure.
 func intSeq() func() int {
     i :=
     return func() int {
         i +=
         return i
     }
 }

 func main() {

     // We call `intSeq`, assigning the result (a function)
     // to `nextInt`. This function value captures its
     // own `i` value, which will be updated each time
     // we call `nextInt`.
     nextInt := intSeq()

     // See the effect of the closure by calling `nextInt`
     // a few times.
     fmt.Println(nextInt())
     fmt.Println(nextInt())
     fmt.Println(nextInt())

     // To confirm that the state is unique to that
     // particular function, create and test a new one.
     newInts := intSeq()
     fmt.Println(newInts())
 }

　　执行上面代码，将得到以下输出结果

3、递归函数

　　示例代码如下：

 package main

 import "fmt"

 // This `fact` function calls itself until it reaches the
 // base case of `fact(0)`.
 func fact(n int) int {
     if n ==  {
         return
     }
     return n * fact(n-)
 }

 func main() {
     fmt.Println(fact())
 }

　　这个fact()函数实际上是调用它自己本身，直到它达到fact(0)时结果退出。

相关链接：

　　Go可变参数的函数实例