I have a string of the form:
codename123
Is there a regular expression that can be used with Regex.Split() to split the alphabetic part and the numeric part into a two-element string array?
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8 Answers
I know you asked for the Split method, but as an alternative you could use named capturing groups:
var numAlpha = new Regex("(?<Alpha>[a-zA-Z]*)(?<Numeric>[0-9]*)");
var match = numAlpha.Match("codename123");
var alpha = match.Groups["Alpha"].Value;
var num = match.Groups["Numeric"].Value;
7 Comments
Alex Essilfie
+1 I remember ever seeing one of such implementations for parsing INI files and I honestly thought it's very wonderful.
Josh
Using named capturing groups sure beats doing
array[0], but that is just me :)
Chris
If the alphabetic part and the numeric part are both required to be present, the regex expression is incorrect. It should be
(?<Alpha>[a-zA-Z]+)(?<Numeric>[0-9]+)
Josh P
Answered my own question: var numAlpha = new Regex("(?<Numeric>[0-9]*/*[0-9]*)(?<Alpha>[a-zA-Z]*)");
Josh
@FllnAngl - This expression is order dependent.
Alpha comes before Numeric |
splitArray = Regex.Split("codename123", @"(?<=\p{L})(?=\p{N})");
will split between a Unicode letter and a Unicode digit.
Comments
Regex is a little heavy handed for this, if your string is always of that form. You could use
"codename123".IndexOfAny(new char[] {'1','2','3','4','5','6','7','8','9','0'})
and two calls to Substring.
1 Comment
user2635088
Yup your way is much faster
IMO, it would be a lot easier to find matches, like:
Regex.Matches("codename123", @"[a-zA-Z]+|\d+")
.Cast<Match>()
.Select(m => m.Value)
.ToArray();
rather than to use Regex.Split.
Comments
A little verbose, but
Regex.Split( "codename123", @"(?<=[a-zA-Z])(?=\d)" );
Can you be more specific about your requirements? Maybe a few other input examples.
3 Comments
Robert Harvey
There might be backslashes in the codename, but other than that, if it works with "code\name123", it should work for my purposes.
Tim Pietzcker
This will split the string into
codename, 1, 2, and 3.
harpo
@Tim, corrected, thanks. I forget that \w matches alphanumeric, not just alpha.
Well, is a one-line only: Regex.Split("codename123", "^([a-z]+)");
Comments
Another simpler way is
string originalstring = "codename123";
string alphabets = string.empty;
string numbers = string.empty;
foreach (char item in mainstring)
{
if (Char.IsLetter(item))
alphabets += item;
if (Char.IsNumber(item))
numbers += item;
}
1 Comment
KMarto
Probably an old question but that is what the regular expression do under the hood, although in an efficient and optimized way
this code is written in java/logic should be same elsewhere
public String splitStringAndNumber(String string) {
String pattern = "(?<Alpha>[a-zA-Z]*)(?<Numeric>[0-9]*)";
Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(string);
if (m.find()) {
return (m.group(1) + " " + m.group(2));
}
return "";
}
