我是 GOlang 的新手,我尝试使用 struct 过滤 GO 中的 struct 切片,其中包含一些用于过滤它的参数。我正在尝试做以下事情,但它对我不起作用。在该代码中,我有过滤器函数,它采用结构的切片,即需要使用 FilterParameter 结构过滤的 GRN。
需要归档的我的结构
type GRN struct {
DocType string `json:"docType"`
GRNNO string `json:"GRNNO"`
PRID string `json:"PRID"`
PRODUCE string `json:"PRODUCE"`
VARIETY string `json:"VARIETY"`
}
manyGRNUsers := []GRN{{"GRNAsset","GRN0000109","PRFAINAPKR0086","Sweetcorn","CP2"},
{"GRNAsset","GRN0000110","PRFAINAPKR0087","Sweetcorn","CP1",},
{"GRNAsset","GRN0000112","PRFAINAPKR0087", "Sweetcorn","CP2",},
{"GRNAsset","GRN0000113","PRFAINAPKR0089","Apple","Gala",}}
将用于过滤器参数的结构。在这里,FilterParameter 中的字段是动态的,如上面的 GRN 结构值。它可以超过两个字段但小于或等于 GRN 结构字段
type FilterParameter struct {
PRODUCE string `json:"PRODUCE"`
VARIETY string `json:"VARIETY"`
}
manyFilterParameter := []FilterParameter{{"Sweetcorn","CP2" }
我尝试了下面的函数,但它对我不起作用,因为我只能使用 FilterParameter 中的一个字段,即 PRODUCE only 而不是动态的
func filter(fu []GRN, su []FilterParameter) (out []GRN) {
f := make(map[string]struct{}, len(su))
for _, u := range su {
f[u.PRODUCE] = struct{}{}
}
for _, u := range fu {
if _, ok := f[u.PRODUCE]; ok {
out = append(out, u)
}
}
return
}
答案 0 :(得分:1)
你不能真正做你想做的事,因为它不可能迭代
struct
的字段(可能带有反射)。对于另一种方法,您可以
使用 map
s 而不是 struct
s,或者更简单,如果你可以明确地使用
函数参数中你关心的字段:
package main
import "fmt"
type GRN struct { DocType, GRNNO, PRID, PRODUCE, VARIETY string }
func filter(in []GRN, produce, variety string) []GRN {
var out []GRN
for _, each := range in {
if each.PRODUCE == produce && each.VARIETY == variety {
out = append(out, each)
}
}
return out
}
func main() {
manyGRNUsers := []GRN{
{"GRNAsset","GRN0000109","PRFAINAPKR0086","Sweetcorn","CP2"},
{"GRNAsset","GRN0000110","PRFAINAPKR0087","Sweetcorn","CP1"},
{"GRNAsset","GRN0000112","PRFAINAPKR0087", "Sweetcorn","CP2"},
{"GRNAsset","GRN0000113","PRFAINAPKR0089","Apple","Gala"},
}
out := filter(manyGRNUsers, "Sweetcorn", "CP2")
fmt.Println(out)
}