Consider two regular expressions:
var regex_A = "Main\.(.+)\.Value";
var regex_B = "M_(.+)_Sp";
I want to be able to replace a string using regex_A as input, and regex_B as the replacement string. But also the other way around. And without supplying additional information like a format string per regex.
Specifically I want to create a replaced_B string from an input_A string. So:
var input_A = "Main.Rotating.Value";
var replaced_B = input_A.RegEx_Awesome_Replace(regex_A, regex_B);
Assert.AreEqual("M_Rotating_Sp", replaced_B);
And this should also work in reverse (thats the reason i can't use a simple string.format for regex_B). Because I don't want to supply a format string for every regular expression (i'm lazy).
var input_B = "M_Skew_Sp";
var replaced_A = input_B.RegEx_Awesome_Replace(regex_B, regex_A);
Assert.AreEqual("Main.Skew.Value", replaced_A);
I have no clue if this exists, or how to call it. Google search finds me all kinds of other regex replaces... not this one.
Update:
So basically I need a way to convert a regular expression to a format string.
var regex_A_format = Regex2Format(regex_A);
Assert.AreEqual("Main.$1.Value", regex_A_format);
and
var regex_B_format = Regex2Format(regex_B);
Assert.AreEqual("M_$1_Sp", regex_B_format);
So what should the RegEx_Awesome_Replace and/or Regex2Format function look like?
Update 2:
I guess the RegEx_Awesome_Replace should look something like (using some code from answers below):
public static class StringExtenstions
{
public static string RegExAwesomeReplace(this string inputString,string searchPattern,string replacePattern)
{
return Regex.Replace(inputString, searchPattern, Regex2Format(replacePattern));
}
}
Which would leave the Regex2Format as an open question.
There is no defined way for one regex to refer to a match found in another regex. Regexes are not format strings.
What you can do is to use Tuples of a format string together with its regex. e.g.
var a = new Tuple<Regex,string>(new Regex(#"(?<=Main\.).+(?=\.Value)"), #"Main.{0}.Value")
var b = new Tuple<Regex,string>(new Regex(#"(?<=M_).+(?=_Sp)"), #"M_{0}_Sp")`
Then you can pass these objects to a common replacement method in any order, like this:
private string RegEx_Awesome_Replace(string input, Tuple<Regex,string> toFind, Tuple<Regex,string> replaceWith)
{
return string.Format(replaceWith.Item2, toFind.Item1.Match(input).Value);
}
You will notice that I have used zero-width positive lookahead assertion and zero-width positive lookbehind assertions in my regexes, to ensure that Value contains exactly the text that I want to replace.
You may also want to add error handling, for cases where the match can not be found. Maybe read about Regex.Match
Since you have already reduced your problem to where you need to change a Regex into a string format (implementing Regex2Format) I will focus my answer just on that part. Note that my answer is incomplete because it doesn't address the full breadth of parsing regex capturing groups, however it works for simple cases.
First thing needed is a Regex that will match Regex capture groups. There is a negative lookbehind to not match escaped bracket symbols. There are other cases that break this regex. E.g. a non-capturing group, wildcard symbols, things between square braces.
private static readonly Regex CaptureGroupMatcher = new Regex(#"(?<!\\)\([^\)]+\)");
The implementation of Regex2Format here basically writes everything outside of capture groups into the output string, and replaces the capture group value by {x}.
static string Regex2Format(string pattern)
{
var targetBuilder = new StringBuilder();
int previousEndIndex = 0;
int formatIndex = 0;
foreach (Match match in CaptureGroupMatcher.Matches(pattern))
{
var group = match.Groups[0];
int endIndex = group.Index;
AppendPart(pattern, previousEndIndex, endIndex, targetBuilder);
targetBuilder.Append('{');
targetBuilder.Append(formatIndex++);
targetBuilder.Append('}');
previousEndIndex = group.Index + group.Length;
}
AppendPart(pattern, previousEndIndex, pattern.Length, targetBuilder);
return targetBuilder.ToString();
}
This helper function writes pattern string values into the output, it currently writes everything except \ characters used to escape something.
static void AppendPart(string pattern, int previousEndIndex, int endIndex, StringBuilder targetBuilder)
{
for (int i = previousEndIndex; i < endIndex; i++)
{
char c = pattern[i];
if (c == '\\' && i < pattern.Length - 1 && pattern[i + 1] != '\\')
{
//backslash not followed by another backslash - it's an escape char
}
else
{
targetBuilder.Append(c);
}
}
}
Test cases
static void Test()
{
var cases = new Dictionary<string, string>
{
{ #"Main\.(.+)\.Value", #"Main.{0}.Value" },
{ #"M_(.+)_Sp(.*)", "M_{0}_Sp{1}" },
{ #"M_\(.+)_Sp", #"M_(.+)_Sp" },
};
foreach (var kvp in cases)
{
if (PatternToStringFormat(kvp.Key) != kvp.Value)
{
Console.WriteLine("Test failed for {0} - expected {1} but got {2}", kvp.Key, kvp.Value, PatternToStringFormat(kvp.Key));
}
}
}
To wrap up, here is the usage:
private static string AwesomeRegexReplace(string input, string sourcePattern, string targetPattern)
{
var targetFormat = PatternToStringFormat(targetPattern);
return Regex.Replace(input, sourcePattern, match =>
{
var args = match.Groups.OfType<Group>().Skip(1).Select(g => g.Value).ToArray<object>();
return string.Format(targetFormat, args);
});
}
Something like this might work
var replaced_B = Regex.Replace(input_A, #"Main\.(.+)\.Value", #"M_$1_Sp");
Are you looking for something like this?
public static class StringExtenstions
{
public static string RegExAwesomeReplace(this string inputString,string searchPattern,string replacePattern)
{
Match searchMatch = Regex.Match(inputString,searchPattern);
Match replaceMatch = Regex.Match(inputString, replacePattern);
if (!searchMatch.Success || !replaceMatch.Success)
{
return inputString;
}
return inputString.Replace(searchMatch.Value, replaceMatch.Value);
}
}
The string extension method returns the string with replaced value for search pattern and replace pattern.
This is how you call:
input_A.RegEx_Awesome_Replace(regex_A, regex_B);
Related
I have a problem to find the pattern that solves the problem in onestep.
The string looks like this:
Text1
Text1$Text2$Text3
Text1$Text2$Text3$Text4$Text5$Text6 etc.
What i want to get is: Take up to 4x Text. If there are more than "4xText" take only the last sign.
Example:
Text1$Text2$Text3$Text4$Text5$Text6 -> Text1$Text2$Text3$Text4&56
My current solution is:
First pattern:
^([^\$]*)\$?([^\$]*)\$?([^\$]*)\$?([^\$]*)\$?
After this i will do a substitution with the first pattern
New string: Text5$Text6
second pattern is:
([^\$])\b
result: 56
combine both and get the result:
Text1$Text2$Text3$Text4$56
For me it is not clear why i cant easily put the second pattern after the first pattern into one pattern. Is there something like an anchor that tells the engine to start the pattern from here like it would do if is would be the only pattern ?
You might use an alternation with a positive lookbehind and then concatenate the matches.
(?<=^(?:[^$]+\$){0,3})[^$]+\$?|[^$](?=\$|$)
Explanation
(?<= Positive lookbehind, assert what is on the left is
^(?:[^$]+\$){0,3} Match 0-3 times any char except $ followed by an optional $
) Close lookbehind
[^$]+\$? Match 1+ times any char except $, then match an optional $
| Or
[^$] Match any char except $
(?=\$|$) Positive lookahead, assert what is directly to the right is either $ or the end of the string
.NET regex demo | C# demo
Example
string pattern = #"(?<=^(?:[^$]*\$){0,3})[^$]*\$?|[^$](?=\$|$)";
string[] strings = {
"Text1",
"Text1$Text2$Text3",
"Text1$Text2$Text3$Text4$Text5$Text6"
};
Regex regex = new Regex(pattern);
foreach (String s in strings) {
Console.WriteLine(string.Join("", from Match match in regex.Matches(s) select match.Value));
}
Output
Text1
Text1$Text2$Text3
Text1$Text2$Text3$Text4$56
I strongly believe regular expression isn't the way to do that. Mostly because of the readability.
You may consider using simple algorithm like this one to reach your goal:
using System;
public class Program
{
public static void Main()
{
var input = "Text1$Text2$Text3$Text4$Text5$Text6";
var parts = input.Split('$');
var result = "";
for(var i=0; i<parts.Length; i++){
result += (i <= 4 ? parts[i] + "$" : parts[i].Substring(4));
}
Console.WriteLine(result);
}
}
There are also linq alternatives :
using System;
using System.Linq;
public class Program
{
public static void Main()
{
var input = "Text1$Text2$Text3$Text4$Text5$Text6";
var parts = input.Split('$');
var first4 = parts.Take(4);
var remainings = parts.Skip(4);
var result2 = string.Join("$", first4) + "$" + string.Join("", remainings.Select( r=>r.Substring(4)));
Console.WriteLine(result2);
}
}
It has to be adjusted to the actual needs but the idea is there
Try this code:
var texts = new string[] {"Text1", "Text1$Text2$Text3", "Text1$Text2$Text3$Text4$Text5$Text6" };
var parsed = texts
.Select(s => Regex.Replace(s,
#"(Text\d{1,3}(?:\$Text\d{1,3}){0,3})((?:\$Text\d{1,3})*)",
(match) => match.Groups[1].Value +"$"+ match.Groups[2].Value.Replace("Text", "").Replace("$", "")
)).ToArray();
// parsed is now: string[3] { "Text1$", "Text1$Text2$Text3$", "Text1$Text2$Text3$Text4$56" }
Explanation:
solution uses regex pattern: (Text\d{1,3}(?:\$Text\d{1,3}){0,3})((?:\$Text\d{1,3})*)
(...) - first capturing group
(?:...) - non-capturing group
Text\d{1,3}(?:\$Text\d{1,3} - match Text literally, then match \d{1,3}, which is 1 up to three digits, \$ matches $ literally
Rest is just repetition of it. Basically, first group captures first four pieces, second group captures the rest, if any.
We also use MatchEvaluator here which is delegate type defined as:
public delegate string MatchEvaluator(Match match);
We define such method:
(match) => match.Groups[1].Value +"$"+ match.Groups[2].Value.Replace("Text", "").Replace("$", "")
We use it to evaluate match, so takee first capturing group and concatenate with second, removing unnecessary text.
It's not clear to me whether your goal can be achieved using exclusively regex. If nothing else, the fact that you want to introduce a new character '&' into the output adds to the challenge, since just plain matching would never be able to accomplish that. Possibly using the Replace() method? I'm not sure that would work though...using only a replacement pattern and not a MatchEvaluator, I don't see a way to recognize but still exclude the "$Text" portion from the fifth instance and later.
But, if you are willing to mix regex with a small amount of post-processing, you can definitely do it:
static readonly Regex regex1 = new Regex(#"(Text\d(?:\$Text\d){0,3})(?:\$Text(\d))*", RegexOptions.Compiled);
static void Main(string[] args)
{
for (int i = 1; i <= 6; i++)
{
string text = string.Join("$", Enumerable.Range(1, i).Select(j => $"Text{j}"));
WriteLine(KeepFour(text));
}
}
private static string KeepFour(string text)
{
Match match = regex1.Match(text);
if (!match.Success)
{
return "[NO MATCH]";
}
StringBuilder result = new StringBuilder();
result.Append(match.Groups[1].Value);
if (match.Groups[2].Captures.Count > 0)
{
result.Append("&");
// Have to iterate (join), because we don't want the whole match,
// just the captured text.
result.Append(JoinCaptures(match.Groups[2]));
}
return result.ToString();
}
private static string JoinCaptures(Group group)
{
return string.Join("", group.Captures.Cast<Capture>().Select(c => c.Value));
}
The above breaks your requirement into three different capture groups in a regex. Then it extracts the captured text, composing the result based on the results.
Given the regular expression
^(aa|bb){1}(a*)(ab){1}$
For the language,
All strings starting with double letters and ends with substring ab
I would like to know if it is possible to print the regex code where the string becomes invalid. This has got to do with regular expressions in Finite Automata.
For example i have these following input set of invalid strings,
abaa
aabb
aaba
I wanted to have an output like this,
abaa ^(aa|bb){1}
aabb ^(aa|bb){1}(a*)
aaba ^(aa|bb){1}(a*)(ab){1}$
You can create a Regex from a string, if it is a malformed pattern it is going to throw an exception. You can create a loop that's going to get substring of the pattern an try to create a regex, if it fails just continue.
Once you have a Regex you can test for a match and store the last pattern that matched the input. So it would be something like this:
public static string FindBestValidRegex(string input, string pattern)
{
var lastMatch = "";
for (int i = 0; i < pattern.Length; i++)
{
try
{
var partialPattern = pattern.Substring(0, i + 1);
var regex = new Regex(partialPattern);
if (regex.IsMatch(input))
{
lastMatch = partialPattern;
}
}
catch { }
}
return lastMatch;
}
Testing:
static void Main(string[] args)
{
var pattern = #"^(aa|bb){1}(a*)(ab){1}$";
Console.WriteLine(FindBestValidRegex("bbb", pattern));
Console.WriteLine(FindBestValidRegex("aabb", pattern));
Console.WriteLine(FindBestValidRegex("aaab", pattern));
Console.WriteLine(FindBestValidRegex("bbaab", pattern));
Console.ReadKey();
}
Output:
^(aa|bb){1}(a*)
^(aa|bb){1}(a*)
^(aa|bb){1}(a*)(ab){1}$
^(aa|bb){1}(a*)(ab){1}$
Assuming I have this input:
/green/blah/agriculture/apple/blah/
I'm only trying to capture and replace the occurrence of apple (need to replace it with orange), so I have this regex
var regex = new Regex("^/(?:green|red){1}(?:/.*)+(apple){1}(?:/.*)");
So I'm grouping sections of the input, but as non-capturing, and only capturing the one I'm concerned with. According to this $` will retrieve everything before the match in the input string, and $' will get everything after, so theoretically the following should work:
"$`Orange$'"
But it only retrieves the match ("apple").
Is it possible to do this with just substitutions and NOT match evaluators and looping through groups?
The issue is that apple can occur anywhere in that url scheme, hence an unknown number of capture groups.
Thanks.
To achieve what you want, I slightly changed your regex.
The new regex looks like this look for the updated version at the end of the answer:
What I am doing here is, I want all the other groups to become captured groups. Doing this I can use them as follow:
String replacement = "$1Orange$2";
string result = Regex.Replace(text, regex.ToString(), replacement);
I am using group 1,2 and 4 and in the middle of everything (where I suspect 'apple') I replace it with Orange.
A complete example looks like this:
using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
String text = "/green/blah/agriculture/apple/blah/hallo/apple";
var regex = new Regex("^(/(?:green|red)/(?:[^/]+/)*?)apple(/.*)");
String replacement = "$1$2Orange$4";
string result = Regex.Replace(text, regex.ToString(), replacement);
Console.WriteLine(result);
}
}
And as well a running example is here
See the updated regex, I needed to change it again to capture things like this:
/green/blah/agriculture/apple/blah/hallo/apple/green/blah/agriculture/apple/blah/hallo/apple
With the above regex it matched the last apple and not the first as prio designated. I changed the regex to this:
var regex = new Regex("^(/(?:green|red)/(?:[^/]+/)*?)apple(/.*)");
I updated the code as well as the running example.
If you really want to replace only the first occurence of apple and dont mind about the URL structure then can you use one of the following methods:
First simply use apple as regex and use the overloaded Replace method.
using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
String text = "/green/blah/agriculture/apple/blah/hallo/apple/green/blah/agriculture/apple/blah/hallo/apple";
var regex = new Regex(Regex.Escape("apple"));
String replacement = "Orange";
string result = regex.Replace(text, replacement.ToString(), 1);
Console.WriteLine(result);
}
}
See working Example
Second is the use of IndexOf and Substring which could be much quick as the use of the regex classes.
See the following Example:
class Program
{
static void Main(string[] args)
{
string search = "apple";
string text = "/green/blah/agriculture/apple/blah/hallo/apple/green/blah/agriculture/apple/blah/hallo/apple";
int idx = text.IndexOf(search);
int endIdx = idx + search.Length;
int secondStrLen = text.Length - endIdx;
if (idx != -1 && idx < text.Length && endIdx < text.Length && secondStrLen > -1)
{
string first = text.Substring(0, idx);
string second = text.Substring(endIdx, secondStrLen);
string result = first + "Orange" + second;
Console.WriteLine(result);
}
}
}
Working Example
I have a string, where the "special areas" are enclosed in curly braces:
{intIncG}/{intIncD}/02-{yy}
I need to iterate through all of these elements inbetween {} and replace them based on their content. What is the best code structure to do it in C#?
I can't just do a replace since I need to know the index of each "speacial area {}" in order to replace it with the correct value.
Regex rgx = new Regex( #"\({[^\}]*\})");
string output = rgx.Replace(input, new MatchEvaluator(DoStuff));
static string DoStuff(Match match)
{
//Here you have access to match.Index, and match.Value so can do something different for Match1, Match2, etc.
//You can easily strip the {'s off the value by
string value = match.Value.Substring(1, match.Value.Length-2);
//Then call a function which takes value and index to get the string to pass back to be susbstituted
}
string.Replace will do just fine.
var updatedString = myString.Replace("{intIncG}", "something");
Do once for every different string.
Update:
Since you need the index of { in order to produce the replacement string (as you commented), you can use Regex.Matches to find the indices of { - each Match object in the Matches collection will include the index in the string.
Use Regex.Replace:
Replaces all occurrences of a character pattern defined by a regular expression with a specified replacement character string.
from msdn
You can define a function and join it's output -- so you'll only need to traverse the parts once and not for every replace rule.
private IEnumerable<string> Traverse(string input)
{
int index = 0;
string[] parts = input.Split(new[] {'/'});
foreach(var part in parts)
{
index++;
string retVal = string.Empty;
switch(part)
{
case "{intIncG}":
retVal = "a"; // or something based on index!
break;
case "{intIncD}":
retVal = "b"; // or something based on index!
break;
...
}
yield return retVal;
}
}
string replaced = string.Join("/", Traverse(inputString));
Is there an easy way to capitalize the first letter of a string and lower the rest of it? Is there a built in method or do I need to make my own?
TextInfo.ToTitleCase() capitalizes the first character in each token of a string.
If there is no need to maintain Acronym Uppercasing, then you should include ToLower().
string s = "JOHN DOE";
s = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(s.ToLower());
// Produces "John Doe"
If CurrentCulture is unavailable, use:
string s = "JOHN DOE";
s = new System.Globalization.CultureInfo("en-US", false).TextInfo.ToTitleCase(s.ToLower());
See the MSDN Link for a detailed description.
CultureInfo.CurrentCulture.TextInfo.ToTitleCase("hello world");
String test = "HELLO HOW ARE YOU";
string s = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(test);
The above code wont work .....
so put the below code by convert to lower then apply the function
String test = "HELLO HOW ARE YOU";
string s = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(test.ToLower());
There are some cases that CultureInfo.CurrentCulture.TextInfo.ToTitleCase cannot handle, for example : the apostrophe '.
string input = CultureInfo.CurrentCulture.TextInfo.ToTitleCase("o'reilly, m'grego, d'angelo");
// input = O'reilly, M'grego, D'angelo
A regex can also be used \b[a-zA-Z] to identify the starting character of a word after a word boundary \b, then we need just to replace the match by its upper case equivalence thanks to the Regex.Replace(string input,string pattern,MatchEvaluator evaluator) method :
string input = "o'reilly, m'grego, d'angelo";
input = Regex.Replace(input.ToLower(), #"\b[a-zA-Z]", m => m.Value.ToUpper());
// input = O'Reilly, M'Grego, D'Angelo
The regex can be tuned if needed, for instance, if we want to handle the MacDonald and McFry cases the regex becomes : (?<=\b(?:mc|mac)?)[a-zA-Z]
string input = "o'reilly, m'grego, d'angelo, macdonald's, mcfry";
input = Regex.Replace(input.ToLower(), #"(?<=\b(?:mc|mac)?)[a-zA-Z]", m => m.Value.ToUpper());
// input = O'Reilly, M'Grego, D'Angelo, MacDonald'S, McFry
If we need to handle more prefixes we only need to modify the group (?:mc|mac), for example to add french prefixes du, de : (?:mc|mac|du|de).
Finally, we can realize that this regex will also match the case MacDonald'S for the last 's so we need to handle it in the regex with a negative look behind (?<!'s\b). At the end we have :
string input = "o'reilly, m'grego, d'angelo, macdonald's, mcfry";
input = Regex.Replace(input.ToLower(), #"(?<=\b(?:mc|mac)?)[a-zA-Z](?<!'s\b)", m => m.Value.ToUpper());
// input = O'Reilly, M'Grego, D'Angelo, MacDonald's, McFry
Mc and Mac are common surname prefixes throughout the US, and there are others. TextInfo.ToTitleCase doesn't handle those cases and shouldn't be used for this purpose. Here's how I'm doing it:
public static string ToTitleCase(string str)
{
string result = str;
if (!string.IsNullOrEmpty(str))
{
var words = str.Split(' ');
for (int index = 0; index < words.Length; index++)
{
var s = words[index];
if (s.Length > 0)
{
words[index] = s[0].ToString().ToUpper() + s.Substring(1);
}
}
result = string.Join(" ", words);
}
return result;
}
ToTitleCase() should work for you.
http://support.microsoft.com/kb/312890
The most direct option is going to be to use the ToTitleCase function that is available in .NET which should take care of the name most of the time. As edg pointed out there are some names that it will not work for, but these are fairly rare so unless you are targeting a culture where such names are common it is not necessary something that you have to worry too much about.
However if you are not working with a .NET langauge, then it depends on what the input looks like - if you have two separate fields for the first name and the last name then you can just capitalize the first letter lower the rest of it using substrings.
firstName = firstName.Substring(0, 1).ToUpper() + firstName.Substring(1).ToLower();
lastName = lastName.Substring(0, 1).ToUpper() + lastName.Substring(1).ToLower();
However, if you are provided multiple names as part of the same string then you need to know how you are getting the information and split it accordingly. So if you are getting a name like "John Doe" you an split the string based upon the space character. If it is in a format such as "Doe, John" you are going to need to split it based upon the comma. However, once you have it split apart you just apply the code shown previously.
CultureInfo.CurrentCulture.TextInfo.ToTitleCase ("my name");
returns ~ My Name
But the problem still exists with names like McFly as stated earlier.
I use my own method to get this fixed:
For example the phrase: "hello world. hello this is the stackoverflow world." will be "Hello World. Hello This Is The Stackoverflow World.". Regex \b (start of a word) \w (first charactor of the word) will do the trick.
/// <summary>
/// Makes each first letter of a word uppercase. The rest will be lowercase
/// </summary>
/// <param name="Phrase"></param>
/// <returns></returns>
public static string FormatWordsWithFirstCapital(string Phrase)
{
MatchCollection Matches = Regex.Matches(Phrase, "\\b\\w");
Phrase = Phrase.ToLower();
foreach (Match Match in Matches)
Phrase = Phrase.Remove(Match.Index, 1).Insert(Match.Index, Match.Value.ToUpper());
return Phrase;
}
The suggestions to use ToTitleCase won't work for strings that are all upper case. So you are gonna have to call ToUpper on the first char and ToLower on the remaining characters.
This class does the trick. You can add new prefixes to the _prefixes static string array.
public static class StringExtensions
{
public static string ToProperCase( this string original )
{
if( String.IsNullOrEmpty( original ) )
return original;
string result = _properNameRx.Replace( original.ToLower( CultureInfo.CurrentCulture ), HandleWord );
return result;
}
public static string WordToProperCase( this string word )
{
if( String.IsNullOrEmpty( word ) )
return word;
if( word.Length > 1 )
return Char.ToUpper( word[0], CultureInfo.CurrentCulture ) + word.Substring( 1 );
return word.ToUpper( CultureInfo.CurrentCulture );
}
private static readonly Regex _properNameRx = new Regex( #"\b(\w+)\b" );
private static readonly string[] _prefixes = {
"mc"
};
private static string HandleWord( Match m )
{
string word = m.Groups[1].Value;
foreach( string prefix in _prefixes )
{
if( word.StartsWith( prefix, StringComparison.CurrentCultureIgnoreCase ) )
return prefix.WordToProperCase() + word.Substring( prefix.Length ).WordToProperCase();
}
return word.WordToProperCase();
}
}
If your using vS2k8, you can use an extension method to add it to the String class:
public static string FirstLetterToUpper(this String input)
{
return input = input.Substring(0, 1).ToUpper() +
input.Substring(1, input.Length - 1);
}
To get round some of the issues/problems that have ben highlighted I would suggest converting the string to lower case first and then call the ToTitleCase method. You could then use IndexOf(" Mc") or IndexOf(" O\'") to determine special cases that need more specific attention.
inputString = inputString.ToLower();
inputString = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(inputString);
int indexOfMc = inputString.IndexOf(" Mc");
if(indexOfMc > 0)
{
inputString.Substring(0, indexOfMc + 3) + inputString[indexOfMc + 3].ToString().ToUpper() + inputString.Substring(indexOfMc + 4);
}
I like this way:
using System.Globalization;
...
TextInfo myTi = new CultureInfo("en-Us",false).TextInfo;
string raw = "THIS IS ALL CAPS";
string firstCapOnly = myTi.ToTitleCase(raw.ToLower());
Lifted from this MSDN article.
Hope this helps you.
String fName = "firstname";
String lName = "lastname";
String capitalizedFName = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(fName);
String capitalizedLName = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(lName);
public static string ConvertToCaptilize(string input)
{
if (!string.IsNullOrEmpty(input))
{
string[] arrUserInput = input.Split(' ');
// Initialize a string builder object for the output
StringBuilder sbOutPut = new StringBuilder();
// Loop thru each character in the string array
foreach (string str in arrUserInput)
{
if (!string.IsNullOrEmpty(str))
{
var charArray = str.ToCharArray();
int k = 0;
foreach (var cr in charArray)
{
char c;
c = k == 0 ? char.ToUpper(cr) : char.ToLower(cr);
sbOutPut.Append(c);
k++;
}
}
sbOutPut.Append(" ");
}
return sbOutPut.ToString();
}
return string.Empty;
}
Like edg indicated, you'll need a more complex algorithm to handle special names (this is probably why many places force everything to upper case).
Something like this untested c# should handle the simple case you requested:
public string SentenceCase(string input)
{
return input(0, 1).ToUpper + input.Substring(1).ToLower;
}