How to Replace characters in a Golang string?

The strings package of Golang has a Replace() function which we can use to replace some characters in a string with a new value. It replaces only a specified "n" occurrences of the substring.

In addition to Replace(), there is a ReplaceAll() function that replaces all the occurrences of a given substring with a new value.

Syntax

func Replace(s, old, new string, n int) string

Where,

• s is the given string

• old is the string which we want to replace

• new is the string which will replace the old string

• n represents the number of characters which we want to replace in the given string.

Example

The following example demonstrates how you can use the Replace() function to replace a substring with a new string.

package main import (    "fmt"    "strings" ) func main() {    // Initializing the Strings    s := "Go Programming Language"    old := "Go"    newstring := "Golang"    n := 1    // Display the Strings    fmt.Println("Original String: ", s)    // Using the Replace Function    testresult := strings.Replace(s, old, newstring, n)    // Display the Replace Output    fmt.Println("Replace Go with Golang:", testresult) }

Output

It will generate the following output −

Original String: Go Programming Language Replace Go with Golang: Golang Programming Language

Example

In this example, we are going to see how to replace a single character with a new value at a particular defined postion or index.

package main import (    "fmt"    "strings" ) func main() {        // Initializing the Strings    x := "Replace String Function"    y := "Go Language"    // Display the Strings    fmt.Println("1st String:", x)    fmt.Println("2nd String:", y)    // Using the Replace Function    test1 := strings.Replace(x, "i", "I", 2)    test2 := strings.Replace(y, "g", "G", -1)    // Display the Replace Output    fmt.Println("\n Replace 'i' with 'I' in the 1st String: \n", test1)    fmt.Println("\n Replace 'g' with 'G' in the 2nd String: \n", test2) }

Output

It will generate the following output −

1st String: Replace String Function 2nd String: Go Language Replace 'i' with 'I' in the 1st String: Replace StrIng FunctIon Replace 'g' with 'G' in the 2nd String: Go LanGuaGe