The problem of implementing in_array in go language
problem description
the problem of implementing in_array in GO language, that is, judging whether a value exists in slice
the environmental background of the problems and what methods you have tried
related codes
/ / Please paste the code text below (do not replace the code with pictures)
func main() {
str1 := "dd"
strArr := []string{"aa","bb","cc","dd"}
exists := inArray(str1, strArr)
fmt.Println(exists)
}
func inArray(need interface{}, needArr []interface{}) bool {
for _,v := range needArr{
if need == v{
return true
}
}
return false
}
what result do you expect? What is the error message actually seen?
need needArr slicetruefalse
:
-sharp command-line-arguments
srctestinarray.go:14:19: cannot use strArr (type [] string) as type [] interface {} in argument to inArray
this is a misunderstanding of the basic syntax. The
inArray function parameter type is [] interface {} means that the element type is interface {} , which means that each element can be of a different type, such as a: = [] interface {} {"test", 123, mapping [int] string {2: "bb"}} .
and if you pass in a specified type like your [] string {} , then every element in the slice must be of type string , which obviously does not match the meaning of the formal parameter [] interface {} of inArray.
therefore, the argument type must also be [] interface {} , where the element can be of any type.
func main() {
str1 := "dd"
strArr := []string{"aa","bb","cc","dd"}
exists := inArray(len(strArr), func(i int) bool {return strArr[i] == str1})
fmt.Println(exists)
}
func inArray(n int, f func(int) bool) bool {
for i := 0; i < n; iPP {
if f(i) {
return true
}
}
return false
}
to find this thing, only the comparison function is related to the type, and the algorithm logic itself has nothing to do with the type, so taking the comparison function as a parameter can achieve the effect of a general algorithm.
func maim() {
var (
str1 interface{}
strArr []interface{}
)
str1 = "dd"
strArr = []interface{}{"aa", "bb", "cc", "dd"}
exists := inArray(str1, strArr)
fmt.Println(exists)
}
func inArray(need interface{}, needArr []interface{}) bool {
for _, v := range needArr {
if need == v {
return true
}
}
return false
}
Go does not support generics. [] xx and [] interface {} are two types.
either write a script to generate a bunch of types of in_array, or sacrifice efficiency with reflect. Look at the scene.
wait for Go2
you can refer to this, and there are also some explanations in the article, from the official wiki
.
Source
