Go可变参数函数的实现

//关键字 函数名(参数1， elems为T类型的可变参数) 返回值类型
func name(params type, elems ...T) returntype{
	// 函数体
}

func append(slice []Type, elems ...Type) []Type

package main

import "fmt"

func find(target int, group ...int) int {
	ishit := false
	index := 0
	for i, v := range group {
		if target == v {
			fmt.Printf("找到元素值:%d,在索引位置:%d\n", v, i)
			ishit = true
			index = i
		}
	}
	if !ishit {
		return -1
	} else {
		return index
	}

}

func main() {
	find(7, 1, 2, 3, 4, 5)
}

package main

import "fmt"

func add(base int, group ...int) {
	total := 0
	for _, v := range group {
		total += v
	}
	total += base
	fmt.Println("total = ", total)
}

func main() {
	add(100, 1, 2, 3, 4, 5)
}

package main

import "fmt"

func find(a int, elems ...int) {
	for i, v := range elems {
		if v == a {
			fmt.Printf("found value %d, at index %d", v, i)
			break
		}
	}
}

func main() {
	a := []int{1, 2, 3, 4, 5}
	find(1, a)  // cannot use a (type []int) as type int in argument to find


}

// 1 函数原型 
func find(a int, elems ...int) 

// 2 函数参数 为切片a 传递到find 等同于 []int{a} 
// 因为切片要求的元素类型为int，传入的确是一个[]int,所以报错
cannot use a (type []int) as type int in argument to find
// 3 go给出的报错信息很友好

package main

import "fmt"

func find(a int, elems ...int) {
	for i, v := range elems {
		if v == a {
			fmt.Printf("found value %d, at index %d", v, i)
			break
		}
	}
}

func main() {
	a := []int{1, 2, 3, 4, 5}
	find(1, a...) // cannot use a (type []int) as type int in argument to find

}

package main

import "fmt"

func changeTest(s ...string) {
	s[0] = "上树捉鸟"
	s[1] = "下河洗澡"
}

func main() {
	s := []string{"好好学习", "天天向上"}
	fmt.Println("传递前： ", s)
	changeTest(s...) // 将切片传递过去，changeTest不会再创建切片
	fmt.Println("传递后： ", s)
}

package main

import "fmt"

func changeTest1(s ...string) {
	s[0] = "上树捉鸟"
	s[1] = "下河洗澡"
	s = append(s, "窈窕淑女", "君子好逑")
	fmt.Println("in changeTest: ", s)
}

func main() {
	s := []string{"好好学习", "天天向上"}
	fmt.Println("传递前： ", s)
	changeTest1(s...) // 将切片传递过去，changeTest不会再创建切片
	fmt.Println("传递后： ", s)
}