.NET - How can you split a "caps" delimited string into an array?

我如何从这个字符串: “ ThisIsMyCapsDlimitedString”

... 到这个字符串: “这是我的大写分隔字符串”

使用 VB.net 中最少的代码行是首选，但也欢迎使用 C # 。

干杯！

24120 次浏览
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也许还有一个更好的解决方案，但是这是我的第一反应:

string myString = "ThisIsMyCapsDelimitedString";


for (int i = 1; i < myString.Length; i++)
{
if (myString[i].ToString().ToUpper() == myString[i].ToString())
{
myString = myString.Insert(i, " ");
i++;
}
}
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格兰特•瓦格纳(Grant Wagner)的精彩评论暂且不提:

Dim s As String = RegularExpressions.Regex.Replace("ThisIsMyCapsDelimitedString", "([A-Z])", " $1")
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string s = "ThisIsMyCapsDelimitedString";
string t = Regex.Replace(s, "([A-Z])", " $1").Substring(1);
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Regex.Replace("ThisIsMyCapsDelimitedString", "(\\B[A-Z])", " $1")
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简单的正则表达式解决方案。不会处理 O’Conner，并在字符串的开始处添加一个空格。

s = "ThisIsMyCapsDelimitedString"
split = Regex.Replace(s, "[A-Z0-9]", " $&");
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Just for a little variety... Here's an extension method that doesn't use a regex.

public static class CamelSpaceExtensions
{
public static string SpaceCamelCase(this String input)
{
return new string(Enumerable.Concat(
input.Take(1), // No space before initial cap
InsertSpacesBeforeCaps(input.Skip(1))
).ToArray());
}


private static IEnumerable<char> InsertSpacesBeforeCaps(IEnumerable<char> input)
{
foreach (char c in input)
{
if (char.IsUpper(c))
{
yield return ' ';
}


yield return c;
}
}
}
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最佳答案

这是我前阵子做的，和 CamelCase 名字的每个组成部分都吻合。

/([A-Z]+(?=$|[A-Z][a-z])|[A-Z]?[a-z]+)/g

例如:

"SimpleHTTPServer" => ["Simple", "HTTP", "Server"]
"camelCase" => ["camel", "Case"]

将其转换为在单词之间插入空格:

Regex.Replace(s, "([a-z](?=[A-Z])|[A-Z](?=[A-Z][a-z]))", "$1 ")

如果你需要处理数字:

/([A-Z]+(?=$|[A-Z][a-z]|[0-9])|[A-Z]?[a-z]+|[0-9]+)/g


Regex.Replace(s,"([a-z](?=[A-Z]|[0-9])|[A-Z](?=[A-Z][a-z]|[0-9])|[0-9](?=[^0-9]))","$1 ")
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为了获得更多的变化，使用普通的老 C # 对象，下面的输出与@MizardX 出色的正则表达式相同。

public string FromCamelCase(string camel)
{   // omitted checking camel for null
StringBuilder sb = new StringBuilder();
int upperCaseRun = 0;
foreach (char c in camel)
{   // append a space only if we're not at the start
// and we're not already in an all caps string.
if (char.IsUpper(c))
{
if (upperCaseRun == 0 && sb.Length != 0)
{
sb.Append(' ');
}
upperCaseRun++;
}
else if( char.IsLower(c) )
{
if (upperCaseRun > 1) //The first new word will also be capitalized.
{
sb.Insert(sb.Length - 1, ' ');
}
upperCaseRun = 0;
}
else
{
upperCaseRun = 0;
}
sb.Append(c);
}


return sb.ToString();
}
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答得好，魔法师！我稍微调整了一下，把数字当作单独的单词，这样“ AddressLine1”就变成了“ Address Line 1”，而不是“ Address Line 1”:

Regex.Replace(s, "([a-z](?=[A-Z0-9])|[A-Z](?=[A-Z][a-z]))", "$1 ")
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Try to use

"([A-Z]*[^A-Z]*)"

结果将适合字母与数字的混合

Regex.Replace("AbcDefGH123Weh", "([A-Z]*[^A-Z]*)", "$1 ");
Abc Def GH123 Weh


Regex.Replace("camelCase", "([A-Z]*[^A-Z]*)", "$1 ");
camel Case
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我需要一个支持缩略词和数字的解决方案:

  • 大写字母后跟小写字母的大写字母
  • 连续数字序列连续数字的序列
  • 连续的大写字母(解释为首字母缩写)——一个新单词可以用最后一个大写字母开头，例如 HTMLGuide = > “ HTML Guide”，“ TheATeam”= > “ The A Team”

你 可以把它当作一句俏皮话:

Regex.Replace(value, @"(?<!^)((?<!\d)\d|(?(?<=[A-Z])[A-Z](?=[a-z])|[A-Z]))", " $1")

一种更易读的方法可能更好:

using System.Text.RegularExpressions;


namespace Demo
{
public class IntercappedStringHelper
{
private static readonly Regex SeparatorRegex;


static IntercappedStringHelper()
{
const string pattern = @"
(?<!^) # Not start
(
# Digit, not preceded by another digit
(?<!\d)\d
|
# Upper-case letter, followed by lower-case letter if
# preceded by another upper-case letter, e.g. 'G' in HTMLGuide
(?(?<=[A-Z])[A-Z](?=[a-z])|[A-Z])
)";


var options = RegexOptions.IgnorePatternWhitespace | RegexOptions.Compiled;


SeparatorRegex = new Regex(pattern, options);
}


public static string SeparateWords(string value, string separator = " ")
{
return SeparatorRegex.Replace(value, separator + "$1");
}
}
}

下面是(XUnit)测试的摘录:

[Theory]
[InlineData("PurchaseOrders", "Purchase-Orders")]
[InlineData("purchaseOrders", "purchase-Orders")]
[InlineData("2Unlimited", "2-Unlimited")]
[InlineData("The2Unlimited", "The-2-Unlimited")]
[InlineData("Unlimited2", "Unlimited-2")]
[InlineData("222Unlimited", "222-Unlimited")]
[InlineData("The222Unlimited", "The-222-Unlimited")]
[InlineData("Unlimited222", "Unlimited-222")]
[InlineData("ATeam", "A-Team")]
[InlineData("TheATeam", "The-A-Team")]
[InlineData("TeamA", "Team-A")]
[InlineData("HTMLGuide", "HTML-Guide")]
[InlineData("TheHTMLGuide", "The-HTML-Guide")]
[InlineData("TheGuideToHTML", "The-Guide-To-HTML")]
[InlineData("HTMLGuide5", "HTML-Guide-5")]
[InlineData("TheHTML5Guide", "The-HTML-5-Guide")]
[InlineData("TheGuideToHTML5", "The-Guide-To-HTML-5")]
[InlineData("TheUKAllStars", "The-UK-All-Stars")]
[InlineData("AllStarsUK", "All-Stars-UK")]
[InlineData("UKAllStars", "UK-All-Stars")]
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下面是一个原型，它将以下内容转换为标题格式:

  • snake_case
  • 骆驼箱
  • PascalCase
  • 判刑案件
  • 标题大小写(保持当前格式)

显然，您只需要自己使用“ ToTitleCase”方法。

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text.RegularExpressions;


public class Program
{
public static void Main()
{
var examples = new List<string> {
"THEQuickBrownFox",
"theQUICKBrownFox",
"TheQuickBrownFOX",
"TheQuickBrownFox",
"the_quick_brown_fox",
"theFOX",
"FOX",
"QUICK"
};


foreach (var example in examples)
{
Console.WriteLine(ToTitleCase(example));
}
}


private static string ToTitleCase(string example)
{
var fromSnakeCase = example.Replace("_", " ");
var lowerToUpper = Regex.Replace(fromSnakeCase, @"(\p{Ll})(\p{Lu})", "$1 $2");
var sentenceCase = Regex.Replace(lowerToUpper, @"(\p{Lu}+)(\p{Lu}\p{Ll})", "$1 $2");
return new CultureInfo("en-US", false).TextInfo.ToTitleCase(sentenceCase);
}
}

输出的控制台如下:

THE Quick Brown Fox
The QUICK Brown Fox
The Quick Brown FOX
The Quick Brown Fox
The Quick Brown Fox
The FOX
FOX
QUICK

Blog Post Referenced

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从 https://stackoverflow.com/a/5796394/4279201实现 psudo 代码

    private static StringBuilder camelCaseToRegular(string i_String)
{
StringBuilder output = new StringBuilder();
int i = 0;
foreach (char character in i_String)
{
if (character <= 'Z' && character >= 'A' && i > 0)
{
output.Append(" ");
}
output.Append(character);
i++;
}
return output;
}
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匹配非大写字母和 大写字母 Unicode 类别: (?<=\P{Lu})(?=\p{Lu})

Dim s = Regex.Replace("CorrectHorseBatteryStaple", "(?<=\P{Lu})(?=\p{Lu})", " ")
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正则表达式比一个简单的循环慢10-12倍:

    public static string CamelCaseToSpaceSeparated(this string str)
{
if (string.IsNullOrEmpty(str))
{
return str;
}


var res = new StringBuilder();


res.Append(str[0]);
for (var i = 1; i < str.Length; i++)
{
if (char.IsUpper(str[i]))
{
res.Append(' ');
}
res.Append(str[i]);


}
return res.ToString();
}
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程序性快速影响:

  /// <summary>
/// Get the words in a code <paramref name="identifier"/>.
/// </summary>
/// <param name="identifier">The code <paramref name="identifier"/></param> to extract words from.
public static string[] GetWords(this string identifier) {
Contract.Ensures(Contract.Result<string[]>() != null, "returned array of string is not null but can be empty");
if (identifier == null) { return new string[0]; }
if (identifier.Length == 0) { return new string[0]; }


const int MIN_WORD_LENGTH = 2;  //  Ignore one letter or one digit words


var length = identifier.Length;
var list = new List<string>(1 + length/2); // Set capacity, not possible more words since we discard one char words
var sb = new StringBuilder();
CharKind cKindCurrent = GetCharKind(identifier[0]); // length is not zero here
CharKind cKindNext = length == 1 ? CharKind.End : GetCharKind(identifier[1]);


for (var i = 0; i < length; i++) {
var c = identifier[i];
CharKind cKindNextNext = (i >= length - 2) ? CharKind.End : GetCharKind(identifier[i + 2]);


// Process cKindCurrent
switch (cKindCurrent) {
case CharKind.Digit:
case CharKind.LowerCaseLetter:
sb.Append(c); // Append digit or lowerCaseLetter to sb
if (cKindNext == CharKind.UpperCaseLetter) {
goto TURN_SB_INTO_WORD; // Finish word if next char is upper
}
goto CHAR_PROCESSED;
case CharKind.Other:
goto TURN_SB_INTO_WORD;
default:  // charCurrent is never Start or End
Debug.Assert(cKindCurrent == CharKind.UpperCaseLetter);
break;
}


// Here cKindCurrent is UpperCaseLetter
// Append UpperCaseLetter to sb anyway
sb.Append(c);


switch (cKindNext) {
default:
goto CHAR_PROCESSED;


case CharKind.UpperCaseLetter:
//  "SimpleHTTPServer"  when we are at 'P' we need to see that NextNext is 'e' to get the word!
if (cKindNextNext == CharKind.LowerCaseLetter) {
goto TURN_SB_INTO_WORD;
}
goto CHAR_PROCESSED;


case CharKind.End:
case CharKind.Other:
break; // goto TURN_SB_INTO_WORD;
}


//------------------------------------------------


TURN_SB_INTO_WORD:
string word = sb.ToString();
sb.Length = 0;
if (word.Length >= MIN_WORD_LENGTH) {
list.Add(word);
}


CHAR_PROCESSED:
// Shift left for next iteration!
cKindCurrent = cKindNext;
cKindNext = cKindNextNext;
}


string lastWord = sb.ToString();
if (lastWord.Length >= MIN_WORD_LENGTH) {
list.Add(lastWord);
}
return list.ToArray();
}
private static CharKind GetCharKind(char c) {
if (char.IsDigit(c)) { return CharKind.Digit; }
if (char.IsLetter(c)) {
if (char.IsUpper(c)) { return CharKind.UpperCaseLetter; }
Debug.Assert(char.IsLower(c));
return CharKind.LowerCaseLetter;
}
return CharKind.Other;
}
enum CharKind {
End, // For end of string
Digit,
UpperCaseLetter,
LowerCaseLetter,
Other
}

测试:

  [TestCase((string)null, "")]
[TestCase("", "")]


// Ignore one letter or one digit words
[TestCase("A", "")]
[TestCase("4", "")]
[TestCase("_", "")]
[TestCase("Word_m_Field", "Word Field")]
[TestCase("Word_4_Field", "Word Field")]


[TestCase("a4", "a4")]
[TestCase("ABC", "ABC")]
[TestCase("abc", "abc")]
[TestCase("AbCd", "Ab Cd")]
[TestCase("AbcCde", "Abc Cde")]
[TestCase("ABCCde", "ABC Cde")]


[TestCase("Abc42Cde", "Abc42 Cde")]
[TestCase("Abc42cde", "Abc42cde")]
[TestCase("ABC42Cde", "ABC42 Cde")]
[TestCase("42ABC", "42 ABC")]
[TestCase("42abc", "42abc")]


[TestCase("abc_cde", "abc cde")]
[TestCase("Abc_Cde", "Abc Cde")]
[TestCase("_Abc__Cde_", "Abc Cde")]
[TestCase("ABC_CDE_FGH", "ABC CDE FGH")]
[TestCase("ABC CDE FGH", "ABC CDE FGH")] // Should not happend (white char) anything that is not a letter/digit/'_' is considered as a separator
[TestCase("ABC,CDE;FGH", "ABC CDE FGH")] // Should not happend (,;) anything that is not a letter/digit/'_' is considered as a separator
[TestCase("abc<cde", "abc cde")]
[TestCase("abc<>cde", "abc cde")]
[TestCase("abc<D>cde", "abc cde")]  // Ignore one letter or one digit words
[TestCase("abc<Da>cde", "abc Da cde")]
[TestCase("abc<cde>", "abc cde")]


[TestCase("SimpleHTTPServer", "Simple HTTP Server")]
[TestCase("SimpleHTTPS2erver", "Simple HTTPS2erver")]
[TestCase("camelCase", "camel Case")]
[TestCase("m_Field", "Field")]
[TestCase("mm_Field", "mm Field")]
public void Test_GetWords(string identifier, string expectedWordsStr) {
var expectedWords = expectedWordsStr.Split(' ');
if (identifier == null || identifier.Length <= 1) {
expectedWords = new string[0];
}


var words = identifier.GetWords();
Assert.IsTrue(words.SequenceEqual(expectedWords));
}
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一个简单的解决方案，它应该比正则表达式解决方案快一个数量级(基于我对这个线程中的顶级解决方案进行的测试) ，特别是当输入字符串的大小增长时:

string s1 = "ThisIsATestStringAbcDefGhiJklMnoPqrStuVwxYz";
string s2;
StringBuilder sb = new StringBuilder();


foreach (char c in s1)
sb.Append(char.IsUpper(c)
? " " + c.ToString()
: c.ToString());


s2 = sb.ToString();

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