如何实现多态变参数的求和？

Question

求问下面的Add2这里怎么实现？sum为interface好像没法任意求和？funcAdd(vars...int)(retint){varsumintfor_,v:=rangevars{//fmt.Println("v",v)sum+=v}returnsum}//这里怎么实现？sum为interface好像没法任意求和？funcAdd2(vars...interface{})(retinterface{}){／*varsuminterface{}for_,v:=rangevars{switchv.(type){caseint:sum+=vcasefloat64:sum+=vcasestring:sum+=v}}*／returnsum}funcmain(){fmt.Println(Add2(1,2))fmt.Println(Add2(1,2,3))fmt.Println(Add2(2.4,3.6,1.0))fmt.Println(Add2("Hello","world","zhong"))}

Answer 1

你想要的是泛型吧？凑合写了一个，忽略与第一个参数不同类型的值。
funcadd(vars...interface{})(retinterface{}){
varsuminterface{}
for_,v:=rangevars{
sum=addTo(sum,v)
}
returnsum
}
funcaddTo(suminterface{},vinterface{})(retinterface{}){
if(sum==nil){
returnv
}
switchv.(type){
caseint:
ifintSum,found:=sum.(int);found{
returnintSum+v.(int)
}
casestring:
ifstrSum,found:=sum.(string);found{
returnstrSum+v.(string)
}
}
returnsum
}