在数组中找到一个元素的下标，找不到返回-1
在javascript中可以这样写:
var a = ['a','b','c','d']console.log(a.indexOf('c')) // 2
* index.go
import ("fmt""strings")type CompareFunc func(interface{}, interface{}) intfunc indexOf(a []interface{}, e interface{}, cmp CompareFunc) int {n := len(a)var i int = 0;for ; i < n; i++ {if cmp(e, a[i]) == 0 {return i;}}return -1;}func main() {as := []string{"apple", "banana", "lime", "橘子", "orange", "橙子", "pineapple", "vine"}// convert []string to []interfaceai := make([]interface{}, len(as))for i, v := range as {ai[i] = v}// Find index of "orange" in arrayfmt.Printf("orange index=%d\n", indexOf(ai, "橙子", func (a interface{}, b interface{}) int {s1 := a.(string)s2 := b.(string)return pare(s1, s2)}));}
* test:
$ go run index.go
orange index=5
橙子 所在数组元素下标为5
golang interface{} 接口用法示例
