Find and replace a character in a string in Go

String manipulation functions are a must have for a programming language and Go has plenty of them. In this tutorial we will see how to find and replace characters in a string.

strings.Replace() function will take in 4 parameters.

1. First is the input string.
2. Second is characters or words to find
3. Third is the new replacement
4. Fourth is the number ( n ) of instances found and to be replaced.

If n < 0, there is no limit on the number of replacements.

To find and replace white spaces from a string

 str := " This string has many spaces that need to be replaced "
 fmt.Println(strings.Replace(str, " ", "", -1))

because we want to remove unlimited instances of spaces in the string. We will use -1 as the fourth parameter. You can use -20 or -5 if you want. Remember the rule :

If n < 0, there is no limit on the number of replacements.

The above code output will be :

Thisstringhasmanyspacesthatneedtobereplaced

Full example code :

 package main

 import (
 "fmt"
 "strings"
 )

 func main() {
 str := " This string has many many spaces that need to be replaced "

 fmt.Println(strings.Replace(str, " ", "", -1))


 str2 := " This string has much much spaces that need to be replaced "

 fmt.Println(strings.Replace(str2, "much", "many", 2))
 }

output :

Thisstringhasmanymanyspacesthatneedtobereplaced

This string has many many spaces that need to be replaced

Reference :

http://golang.org/pkg/strings/#Replace