Golang : Remove characters from string example



Tags : golang strip-charactersindex-rune strings map

Problem:

You have a string and you want to remove certain characters from the string base on a set of characters. You've tried using strings.Replace() function to remove the unwanted characters, but you found out that it removes one character at a time, not a set of characters. To remove a set of characters with strings.Replace() function requires looping and can be inefficient. Is there a better way to remove a set of characters from a string?

Solution:

Combine strings.Map() and strings.IndexRune() functions to remove a set of unwanted characters from the string.

Here you go!


 package main

 import (
 "fmt"
 "strings"
 )

 func removeCharacters(input string, characters string) string {
 filter := func(r rune) rune {
 if strings.IndexRune(characters, r) < 0 {
 return r
 }
 return -1
 }

 return strings.Map(filter, input)

 }

 func main() {

 str := "你好吗? 我好! 好我好!? 你好好!"
 stripped := strings.Replace(str, "我好", "", -1) // Replace will work with a single unicode
 fmt.Println("Before : ", str)
 fmt.Println("After : ", stripped)

 str = "Happy Go Lucky!"
 stripped = strings.Replace(str, "a", "", -1) // only works with a single character
 fmt.Println("Before : ", str)
 fmt.Println("After : ", stripped)

 str = "Happy Go Lucky!"
 stripped = strings.Replace(str, "aGo", "", -1) // but NOT with a set of characters
 fmt.Println("Before : ", str)
 fmt.Println("After : ", stripped)

 fmt.Println("-------------------------------------------------")
 str = "你好吗? 我好! 好我好!? 你好好!"
 stripped = removeCharacters(str, "我好") // now with remove/strip a set of unicode characters
 fmt.Println("Before : ", str)
 fmt.Println("After : ", stripped)

 str = "Happy Go Lucky!"
 stripped = removeCharacters(str, "aGo") // will work with a set of characters
 fmt.Println("Before : ", str)
 fmt.Println("After : ", stripped)

 }

Output:

Before : 你好吗? 我好! 好我好!? 你好好!

After : 你好吗? ! 好!? 你好好!

Before : Happy Go Lucky!

After : Hppy Go Lucky!

Before : Happy Go Lucky!

After : Happy Go Lucky!


Before : 你好吗? 我好! 好我好!? 你好好!

After : 你吗? ! !? 你!

Before : Happy Go Lucky!

After : Hppy Lucky!

References:

https://golang.org/pkg/strings/#IndexRune

https://golang.org/pkg/strings/#Map

https://www.socketloop.com/tutorials/golang-remove-dashes-or-any-character-from-string

  See also : Find and replace a character in a string in Go



Tags : golang strip-charactersindex-rune strings map

By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


Advertisement