Golang : Use regular expression to get all upper case or lower case characters example

This is an add-on for the previous tutorial on how to get all upper case or lower case characters example. In this example, we will explore the a different version that use a regular expression to achieve the same objective.

Here you go!

 package main

 import (
 "fmt"
 "regexp"
 )

 func removeDelimAndLowerCase(str string) string {
 regExp := regexp.MustCompile(`[^[:upper:]]`)
 return regExp.ReplaceAllString(str, "")
 }

 func removeDelimAndUpperCase(str string) string {
 regExp := regexp.MustCompile(`[^[:lower:]]`)
 return regExp.ReplaceAllString(str, "")
 }

 func main() {
 str := "This a string with some UpperCase Characters."

 allUpper := removeDelimAndLowerCase(str)
 fmt.Println("All uppercase : ", allUpper)

 allLower := removeDelimAndUpperCase(str)
 fmt.Println("All lowercase : ", allLower)

 }

Output:

All uppercase : TUCC

All lowercase : hisastringwithsomepperaseharacters

NOTES:

It is definitely faster to use regular expression to parse string, but sometimes it can be hard to read for other programmers or your teammates. To keep things simple, try to use non-regular expression solution if possible. Ability is read source code is more important that ability to write codes.

Happy coding!