英文:
Iterate through struct in golang without reflect
问题
我有一个类似这样的结构体：
import (
"fmt"
)
type Node struct {
m []string
o []string
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var v = Node{m: mm, o: oo}
for i := 0; i < len(v.m); i++ {
fmt.Println(v.m[i] + "," + v.o[i])
}
}
我得到的输出是：
[abc def]
[111 222]
我希望得到的输出是：
abc,111
def,222
我不想使用 reflect 包，因为我尽可能想使用原生的 Go 内置功能。如果这变得太麻烦，我会退回到 reflect 包。
英文:
I have a struct like this
import (
"fmt"
)
type Node struct {
m []string
o []string
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var v = Node{m: mm, o: oo}
for _, d := range []interface{}{v.m, v.o} {
fmt.Println(d)
}
}
The output I get is,
[abc def]
[111 222]
My desired output is,
abc,111
def,222
I don't want to use reflect package because, I want to use native go built-ins as much as possible. If it becomes too burdensome I will fall back on reflect package.
答案1
得分: 1
你不想使用reflect包的原因是什么？像这个问题https://stackoverflow.com/questions/18926303/iterate-through-a-struct-in-go和https://stackoverflow.com/questions/21246642/iterate-over-string-fields-in-struct这样的问题？
从前一个问题来看，似乎是的，你可以通过迭代字段的interface来实现无需使用reflect进行迭代，示例代码如下：
package main
import (
"fmt"
)
type Foo struct {
num int
str string
}
func main() {
foo := &Foo{42, "Hello"} // struct with fields of many types...
for _, data := range []interface{}{foo.num, foo.str} {
fmt.Println(data)
}
}
希望对你有帮助！
英文:
Is there a reason you don't want to use the reflect package? like https://stackoverflow.com/questions/18926303/iterate-through-a-struct-in-go and https://stackoverflow.com/questions/21246642/iterate-over-string-fields-in-struct ?
From the former question, it seems like, yeah you can iterate without reflect by iterating through an interface of the fields, https://play.golang.org/p/bPWUII_D7q
package main
import (
"fmt"
)
type Foo struct {
num int
str string
}
func main() {
foo := &Foo{42, "Hello"} // struct with fields of many types...
for _, data := range []interface{}{foo.num, foo.str} {
fmt.Println(data)
}
}
答案2
得分: 1
**编辑：**我刚意识到我的输出与你的不匹配，你是否希望字母与数字配对？如果是的话，你需要重新调整你的代码。
你可以使用strings.Join和类型切换语句来实现：
package main
import (
"fmt"
"strings"
)
type Node struct {
m []string
o []string
p []int
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var pp = []int{1, 2, 3}
var v = Node{m: mm, o: oo, p: pp}
for _, d := range []interface{}{v.m, v.o, v.p} {
switch d.(type) {
case []string:
fmt.Println(strings.Join(d.([]string), ","))
default:
fmt.Println(d)
}
}
}
输出结果为：
abc,def
111,222
[1 2 3]
英文:
Edit: I just realized my output doesn't match yours, do you want the letters paired with the numbers? If so then you'll need to re-work what you have.
You can use strings.Join and a type switch statement to accomplish this:
https://play.golang.org/p/ygtdxv02uK
package main
import (
"fmt"
"strings"
)
type Node struct {
m []string
o []string
p []int
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var pp = []int{1, 2, 3}
var v = Node{m: mm, o: oo, p: pp}
for _, d := range []interface{}{v.m, v.o, v.p} {
switch d.(type) {
case []string:
fmt.Println(strings.Join(d.([]string), ","))
default:
fmt.Println(d)
}
}
}
The output is:
abc,def
111,222
[1 2 3]
答案3
得分: 0
这是我所做的：
package main
import (
"fmt"
)
type Node struct {
m []string
o []string
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var v = Node{m: mm, o: oo}
for i := range v.m {
fmt.Println(v.m[i], v.o[i])
}
}
这给我提供了我想要的输出。只有一件事，我必须写v.m，所以我想我仍然应该使用reflect包。
英文:
Here is what I did,
package main
import (
"fmt"
)
type Node struct {
m []string
o []string
}
func main() {
var mm = []string{"abc", "def"}
var oo = []string{"111", "222"}
var v = Node{m: mm, o: oo}
for i := range v.m {
fmt.Println(v.m[i],v.o[i])
}
}
This gives me my desired output. Just one thing is I have to write v.m so I suppose I should still use reflect package.
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