[英]How fix Issue in Struct using Go?
我在使用 Go 的 Struct 中有問題。
示例代碼:
package main
import (
"fmt"
)
type KeyVal struct {
Key interface{}
Value interface{}
}
type KeyVals []KeyVal
func (kvs *KeyVals) AddOld(key interface{}, val interface{}) {
kv := KeyVal{key, val,typ}
*kvs = append(*kvs, kv)
}
func (kvs *KeyVals) Add(key interface{}, val interface{}){
var flag,id = kvs.Exist(key)
if flag == true {
//kv := KeyVal{key,"Updated!"}
//*kvs=append(*kvs,kv)
//fmt.Println(*kvs[0].Key)
//update value of them
kv := KeyVal{key,val}
kvs[id]=kv
//*kvs[id]=kv
//fmt.Println("old set with id =",id,",","value =",kvs)
}else{
kv := KeyVal{key, val}
*kvs = append(*kvs, kv)
}
}
func (kvs *KeyVals) Search(skey interface{}) (bool,interface{},interface{}) {
for n, kv := range *kvs {
key := kv.Key
val := kv.Value
if(key == skey){
return true,n,val
}
}
return false,nil,nil
}
func (kvs *KeyVals) Exist(skey interface{})(bool,int) {
for n, kv := range *kvs {
key := kv.Key
if(key == skey){
return true,n
}
}
return false,-1
}
func main() {
var kvs keyval.KeyVals
kvs.Add("key1","value1")
kvs.Add("key2","value2")
kvs.Add("key3","value3")
kvs.Add("key4",5)
kvs.Add("key5",5.2)
kvs.Add("key5","new....")//this should update value of this key. but not work!
var flag,id,value = kvs.Search("key5")
fmt.Println(flag,id,value)
for _, kv := range kvs {
key := kv.Key
val := kv.Value
fmt.Println("", key," ==> ", val)
}
}
我的問題:
在函數 Add() 中, kvs[id]=kv
有錯誤! 怎么修?
Exist()
和Search()
速度好嗎? 不能做得更好嗎?
我嘗試將索引名稱添加到代碼中: type KeyVals []KeyVal
更改為:意思是: type KeyVals [interface{}]KeyVal
或type KeyVals [string]KeyVal
...但錯誤!
1 . 在函數 Add() 中, kvs[id]=kv 有錯誤! 怎么修?
kvs
是 *KeyVals 類型,它不支持索引您可以使用
(*kvs)[id] = kv
2 . Exist() 和 Search() 的速度好嗎? 不能做得更好嗎?
您可以使用哈希圖而不是數組來實現更快的搜索/存在函數。您可以將search
和exist
結合到一個函數中。
3 . 我嘗試將索引名稱添加到代碼:鍵入 KeyVals []KeyVal 更改為:意思是:鍵入 KeyVals [interface{}]KeyVal 或鍵入 KeyVals [string]KeyVal ...但錯誤!
類型聲明是錯誤的。更接近這些的類型是map[interface{}]interface{}
或map [string]interface{}
這是有效的更新代碼,我使用 Hashmap 而不是數組和數組來跟蹤訂單
代碼
package main
import (
"fmt"
)
type KeyVals struct {
keyVals map[string]interface{}
KeysInOrder []string
}
func (kvs *KeyVals) Add(key string, val interface{}) {
if kvs.keyVals == nil {
kvs.keyVals = make(map[string]interface{})
}
if _, ok := kvs.keyVals[key]; ok {
kvs.keyVals[key] = val
return
}
kvs.keyVals[key] = val
kvs.KeysInOrder = append(kvs.KeysInOrder, key)
return
}
func (kvs KeyVals) Search(key string) (interface{}, bool) {
val, found := kvs.keyVals[key]
return val, found
}
func main() {
var kvs KeyVals
kvs.Add("key1", "value1")
kvs.Add("key2", "value2")
kvs.Add("key3", "value3")
kvs.Add("key4", 5)
kvs.Add("key5", 5.2)
kvs.Add("key5", "new....") //this should update value of this key. but not work!
value, ok := kvs.Search("key5")
fmt.Println(value, ok)
for _, key := range kvs.KeysInOrder {
value, _ = kvs.Search(key)
fmt.Println(key, " ==> ", value)
}
}
這是播放鏈接:鏈接
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