Golang : Get all upper case or lower case characters from string example
Problem:
You have a string and you want to get all the uppercase characters in the string. For example, you want to get the characters of A,O and H from the string "Ace Of Hearts" and use the AOH
to make a key for your string map. How to do that?
Solution:
Use unicode.IsLower()
function to determine if the character is lowercase or not. If not, then push the characters into a slice or form a string with strings.Join()
function.
Here you go!
package main
import (
"fmt"
"regexp"
"strings"
"text/scanner"
"unicode"
)
// faster way to get rid delimiters
// for string without unicode
func removeDelimString(str string) string {
// alphanumeric (== [0-9A-Za-z])
// \s is a white space character
regExp := regexp.MustCompile(`[^[:alnum:]\s]`)
return regExp.ReplaceAllString(str, "")
}
// get all upper case characters from string
// to get all lower case characters, just remove the exclamation mark !
// infront of unicode.IsLower()
func getUpperCaseChars(str string) []string {
tokens := removeDelimString(str)
var result []string
for _, char := range tokens {
if !unicode.IsLower(char) && char != ' ' {
fmt.Println(scanner.TokenString(char))
result = append(result, scanner.TokenString(char))
}
}
return result
}
func main() {
str := "This a string with some UpperCase Characters."
temp := getUpperCaseChars(str)
for k, v := range temp {
fmt.Println(k, v)
}
// form into a UPPERCASE string
upper := removeDelimString(strings.Join(temp, ""))
fmt.Println(upper)
}
Output:
"T"
"U"
"C"
"C"
0 "T"
1 "U"
2 "C"
3 "C"
TUCC
References:
https://www.socketloop.com/tutorials/golang-how-to-join-strings
https://golang.org/pkg/unicode/#IsLower
https://socketloop.com/tutorials/golang-break-string-into-a-slice-of-characters-example
See also : Golang : Break string into a slice of characters example
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
Tutorials
+11.8k Generate salted password with OpenSSL example
+8.5k Golang : Launch Mac OS X Preview (or other OS) application from your program example
+5.7k Golang : Derive cryptographic key from passwords with Argon2
+7.9k Golang : GMail API create and send draft with simple upload attachment example
+20.6k Golang : Setting up/configure AWS credentials with official aws-sdk-go
+7.2k Golang : How To Use Panic and Recover
+7.7k Linux/Unix : fatal: the Postfix mail system is already running
+3.8k JavaScript: Add marker function on Google Map
+61.5k Golang : Convert HTTP Response body to string
+29.3k Golang : Interpolating or substituting variables in string examples
+3.8k Golang : How to pass data between controllers with JSON Web Token
+3.8k Mac OSX : Get disk partitions' size, type and name