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
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