在golang中替换第N个出现的字符串

huangapple
go评论121阅读模式
英文:

Replace Nth occurrence of string in golang

问题

如何在golang中替换第n个（在这种情况下是第二个）字符串出现？以下代码将示例字符串optimismo from optimism替换为o from optimism，而我希望它是optimismo from。

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"strings"
  6. )
  8. func main() {
  9. 	mystring := "optimismo from optimism"
  10. 	excludingSecond := strings.Replace(mystring, "optimism", "", 1)
  11. 	fmt.Println(excludingSecond)
  12. }

你可以使用strings.Replace函数来替换字符串。该函数的第三个参数是要替换的字符串，第四个参数是替换的次数。在你的代码中，你将optimism替换为空字符串，并指定替换一次。如果你想替换第二次出现的字符串，可以将第四个参数设置为2。

英文:

How do I replace the nth (in this case second) occurrence of a string in golang? The following code replaces the example string optimismo from optimism with o from optimism when I want it to be optimismo from

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"strings"
  6. )
  8. func main() {
  9. 	mystring := "optimismo from optimism"
  10. 	excludingSecond := strings.Replace(mystring, "optimism", "", 1)
  11. 	fmt.Println(excludingSecond)
  12. }

答案1

得分: 11

对于任何在这篇帖子上遇到问题并且想要替换最后一次出现的人

  1. package main
  3. import (
  4.     "fmt"
  5.     "strings"
  6. )
  8. func main() {
  9.     mystring := "optimismo from optimism"
  11.     i := strings.LastIndex(mystring, "optimism")
  12.     excludingLast := mystring[:i] + strings.Replace(mystring[i:], "optimism", "", 1)
  13.     fmt.Println(excludingLast)
  14. }

如果有任何问题，请告诉我。

英文:

For anyone stumbling on this post and is looking to replace the LAST occurrence

  1. package main
  3. import (
  4.     "fmt"
  5.     "strings"
  6. )
  8. func main() {
  9.     mystring := "optimismo from optimism"
  11.     i := strings.LastIndex(mystring, "optimism")
  12.     excludingLast := mystring[:i] + strings.Replace(mystring[i:], "optimism", "", 1)
  13.     fmt.Println(excludingLast)
  14. }

答案2

得分: 7

例如，

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"strings"
  6. )
  8. // 用新的字符串替换s中第n个出现的old字符串。
  9. func replaceNth(s, old, new string, n int) string {
  10. 	i := 0
  11. 	for m := 1; m <= n; m++ {
  12. 		x := strings.Index(s[i:], old)
  13. 		if x < 0 {
  14. 			break
  15. 		}
  16. 		i += x
  17. 		if m == n {
  18. 			return s[:i] + new + s[i+len(old):]
  19. 		}
  20. 		i += len(old)
  21. 	}
  22. 	return s
  23. }
  25. func main() {
  26. 	s := "optimismo from optimism"
  27. 	fmt.Printf("%q\n", s)
  28. 	t := replaceNth(s, "optimism", "", 2)
  29. 	fmt.Printf("%q\n", t)
  30. }

输出：

  1. "optimismo from optimism"
  2. "optimismo from "
英文:

For example,

  1. package main
  3. import (
  4. 	&quot;fmt&quot;
  5. 	&quot;strings&quot;
  6. )
  8. // Replace the nth occurrence of old in s by new.
  9. func replaceNth(s, old, new string, n int) string {
  10. 	i := 0
  11. 	for m := 1; m &lt;= n; m++ {
  12. 		x := strings.Index(s[i:], old)
  13. 		if x &lt; 0 {
  14. 			break
  15. 		}
  16. 		i += x
  17. 		if m == n {
  18. 			return s[:i] + new + s[i+len(old):]
  19. 		}
  20. 		i += len(old)
  21. 	}
  22. 	return s
  23. }
  25. func main() {
  26. 	s := &quot;optimismo from optimism&quot;
  27. 	fmt.Printf(&quot;%q\n&quot;, s)
  28. 	t := replaceNth(s, &quot;optimism&quot;, &quot;&quot;, 2)
  29. 	fmt.Printf(&quot;%q\n&quot;, t)
  30. }

Output:

  1. &quot;optimismo from optimism&quot;
  2. &quot;optimismo from &quot;

答案3

得分: 3

如果你总是知道会有两个，你可以使用https://godoc.org/strings#Index来找到第一个的索引，然后在之后的所有内容上进行替换，最后将它们组合在一起。

  1. func main() {
  2.     search := "optimism"
  3.     mystring := "optimismo from optimism"
  4.     
  5.     // 找到第一个的索引并加上长度以获取单词的结尾
  6.     ind := strings.Index(mystring, search)
  7.     if ind == -1 {
  8.         fmt.Println("不存在")
  9.         return // 错误情况
  10.     }
  11.     ind += len(search)
  13.     excludingSecond := mystring[:ind]
  14.     
  15.     // 在第一个之后的所有内容上运行替换
  16.     excludingSecond += strings.Replace(mystring[ind:], search, "", 1)
  17.     fmt.Println(excludingSecond)
  18. }

希望对你有帮助！

英文:

If you always know there will be two, you could use https://godoc.org/strings#Index to find the index of the first, then do the replace on everything after, finally combining them together.

https://play.golang.org/p/CeJFViNjgH

  1. func main() {
  2. 	search := &quot;optimism&quot;
  3. 	mystring := &quot;optimismo from optimism&quot;
  4. 	
  5. 	// find index of the first and add the length to get the end of the word
  6. 	ind := strings.Index(mystring, search)
  7. 	if ind == -1 {
  8. 		fmt.Println(&quot;doesn&#39;t exist&quot;)
  9. 		return // error case
  10. 	}
  11. 	ind += len(search)
  13. 	excludingSecond := mystring[:ind]
  14. 	
  15. 	// run replace on everything after the first one
  16. 	excludingSecond += strings.Replace(mystring[ind:], search, &quot;&quot;, 1)
  17. 	fmt.Println(excludingSecond)
  18. }

huangapple
  • 本文由 发表于 2017年5月24日 04:43:17
  • 转载请务必保留本文链接：https://go.coder-hub.com/44144641.html
  • go
  • string
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定