Golang：如何将一个由字符串和数字组成的整数数组求和

huangapple
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英文:

Golang: how to sum an array of integers as strings and numbers

问题

如何在GoLang中对包含字符串和数字混合类型的整数数组求和？

下面的代码出现错误："mismatched types int and any" 和 "cannot initialize 1 variables with 2 values"。

是否有类似JavaScript解决方案的方法？
https://stackoverflow.com/questions/57893236/function-that-sums-array-numbers-including-numbers-as-strings

错误的代码：

  1. import (
  2. "fmt"
  3. "strconv"
  4. )
  6. func main() {
  7.   fmt.Println(sum([]any{9, 1, "8", "2"})) // 这应该输出20
  8. }
  10. func sum(arr []any) int {
  11.   n:=0
  12.   for _, v := range arr{
  13.     temp:=strconv.Atoi(v) // 错误：无法用2个值初始化1个变量
  14.     n+=temp // 错误：类型不匹配 int 和 any
  15.   }
  16.   return n
  17. }

这个也会出错：

  1.   n:=0
  2.   for _, v := range arr{
  3.     temp:=0
  4.     if reflect.TypeOf(v)=="string"{
  5.       temp=strconv.Atoi(v)
  6.     } else {
  7.       temp=v
  8.     }
  9.     n+=temp
  10.   }
  11.   return n
英文:

How to sum an array of integers with mixed types of strings and numbers in GoLang?
Code below errors with "mismatched types int and any" and "cannot initialize 1 variables with 2 values".

Is there something like this JavaScript solution?
https://stackoverflow.com/questions/57893236/function-that-sums-array-numbers-including-numbers-as-strings

errored code:

  1. import (
  2. "fmt"
  3. "strconv"
  4. )
  6. func main() {
  7.   fmt.Println(sum([]any{9, 1, "8", "2"})) // this should output 20
  8. }
  10. func sum(arr []any) int {
  11.   n:=0
  12.   for _, v := range arr{
  13.     temp:=strconv.Atoi(v) //err: cannot initialize 1 variables with 2 values
  14.     n+=temp //err: mismatched types int and any
  15.   }
  16.   return n
  17. }

This also errors:

  1.   n:=0
  2.   for _, v := range arr{
  3.     temp:=0
  4.     if reflect.TypeOf(v)=="string"{
  5.       temp=strconv.Atoi(v)
  6.     } else {
  7.       temp=v
  8.     }
  9.     n+=temp
  10.   }
  11.   return n
  13. </details>
  16. # 答案1
  17. **得分**: 4
  19. 使用[type switch](https://go.dev/ref/spec#Type_switches)来适当处理整数和字符串值。
  21. `temp:=strconv.Atoi(v)`返回两个值。将结果分配给两个变量。处理错误返回。
  23. 以下是修复后的代码：
  25. ```go
  26. func sum(arr []any) int {
  27.     n := 0
  28.     for _, v := range arr {
  29.         switch v := v.(type) {
  30.         case int:
  31.             n += v
  32.         case string:
  33.             i, err := strconv.Atoi(v)
  34.             if err != nil {
  35.                 panic(err)
  36.             }
  37.             n += i
  38.         default:
  39.             panic(fmt.Sprintf("unsupported type %T", v))
  40.         }
  41.     }
  42.     return n
  43. }

为了完整起见，这里还有一个使用反射的版本的函数。但是，推荐使用类型切换版本的函数。

  1. func sum(arr []any) int {
  2.     n := 0
  3.     for _, v := range arr {
  4.         v := reflect.ValueOf(v)
  5.         if v.Kind() == reflect.Int {
  6.             n += int(v.Int())
  7.         } else if v.Kind() == reflect.String {
  8.             i, err := strconv.Atoi(v.String())
  9.             if err != nil {
  10.                 panic(err)
  11.             }
  12.             n += i
  13.         } else {
  14.             panic(fmt.Sprintf("unsupported type %s", v.Type()))
  15.         }
  16.     }
  17.     return n
  18. }
英文:

> count+=temp //err: mismatched types int and any

Use a type switch to handle integer and string values as appropriate.

> temp:=strconv.Atoi(v) //err: cannot initialize 1 variables with 2 values

strconv.Atoi returns two values. Assign the result to two variables. Handle the error return.

Here's the code with the fixes:

  1. func sum(arr []any) int {
  2. 	n := 0
  3. 	for _, v := range arr {
  4. 		switch v := v.(type) {
  5. 		case int:
  6. 			n += v
  7. 		case string:
  8. 			i, err := strconv.Atoi(v)
  9. 			if err != nil {
  10. 				panic(err)
  11. 			}
  12. 			n += i
  13. 		default:
  14. 			panic(fmt.Sprintf(&quot;unsupported type %T&quot;, v))
  15. 		}
  16. 	}
  17. 	return n
  18. }

For completeness, here's a version of the function that uses reflection. The type switch version of the function is preferred over reflection.

  1. func sum(arr []any) int {
  2. 	n := 0
  3. 	for _, v := range arr {
  4. 		v := reflect.ValueOf(v)
  5. 		if v.Kind() == reflect.Int {
  6. 			n += int(v.Int())
  7. 		} else if v.Kind() == reflect.String {
  8. 			i, err := strconv.Atoi(v.String())
  9. 			if err != nil {
  10. 				panic(err)
  11. 			}
  12. 			n += i
  13. 		} else {
  14. 			panic(fmt.Sprintf(&quot;unsupported type %s&quot;, v.Type()))
  15. 		}
  16. 	}
  17. 	return n
  18. }

huangapple
  • 本文由 发表于 2022年10月31日 09:02:00
  • 转载请务必保留本文链接：https://go.coder-hub.com/74257846.html
  • go
  • integer
  • string
  • types
  • variables
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