给定字符串“ThisStringHasNoSpacesButItDoesHaveCapitals”，什么是在大写字母之前添加空格的最好方法。所以结尾字符串是"This string Has No space But It Does Have大写"
下面是我使用正则表达式的尝试
System.Text.RegularExpressions.Regex.Replace(value, "[A-Z]", " $0")
当前回答
下面是在SQL中如何做到这一点
create FUNCTION dbo.PascalCaseWithSpace(@pInput AS VARCHAR(MAX)) RETURNS VARCHAR(MAX)
BEGIN
declare @output varchar(8000)
set @output = ''
Declare @vInputLength INT
Declare @vIndex INT
Declare @vCount INT
Declare @PrevLetter varchar(50)
SET @PrevLetter = ''
SET @vCount = 0
SET @vIndex = 1
SET @vInputLength = LEN(@pInput)
WHILE @vIndex <= @vInputLength
BEGIN
IF ASCII(SUBSTRING(@pInput, @vIndex, 1)) = ASCII(Upper(SUBSTRING(@pInput, @vIndex, 1)))
begin
if(@PrevLetter != '' and ASCII(@PrevLetter) = ASCII(Lower(@PrevLetter)))
SET @output = @output + ' ' + SUBSTRING(@pInput, @vIndex, 1)
else
SET @output = @output + SUBSTRING(@pInput, @vIndex, 1)
end
else
begin
SET @output = @output + SUBSTRING(@pInput, @vIndex, 1)
end
set @PrevLetter = SUBSTRING(@pInput, @vIndex, 1)
SET @vIndex = @vIndex + 1
END
return @output
END
其他回答
之前所有的回答看起来都太复杂了。
我有一个字符串，它混合使用了大写字母和_，string. replace()来生成_，" "并使用下面的代码在大写字母处添加一个空格。
for (int i = 0; i < result.Length; i++)
{
if (char.IsUpper(result[i]))
{
counter++;
if (i > 1) //stops from adding a space at if string starts with Capital
{
result = result.Insert(i, " ");
i++; //Required** otherwise stuck in infinite
//add space loop over a single capital letter.
}
}
}
这里有一个更彻底的解决方案，它没有在单词前面放空格:
注意:我使用了多个regex(不简洁，但它也可以处理首字母缩略词和单字母单词)
Dim s As String = "ThisStringHasNoSpacesButItDoesHaveCapitals"
s = System.Text.RegularExpressions.Regex.Replace(s, "([a-z])([A-Z](?=[A-Z])[a-z]*)", "$1 $2")
s = System.Text.RegularExpressions.Regex.Replace(s, "([A-Z])([A-Z][a-z])", "$1 $2")
s = System.Text.RegularExpressions.Regex.Replace(s, "([a-z])([A-Z][a-z])", "$1 $2")
s = System.Text.RegularExpressions.Regex.Replace(s, "([a-z])([A-Z][a-z])", "$1 $2") // repeat a second time
In:
"ThisStringHasNoSpacesButItDoesHaveCapitals"
"IAmNotAGoat"
"LOLThatsHilarious!"
"ThisIsASMSMessage"
Out:
"This String Has No Spaces But It Does Have Capitals"
"I Am Not A Goat"
"LOL Thats Hilarious!"
"This Is ASMS Message" // (Difficult to handle single letter words when they are next to acronyms.)
下面是在SQL中如何做到这一点
create FUNCTION dbo.PascalCaseWithSpace(@pInput AS VARCHAR(MAX)) RETURNS VARCHAR(MAX)
BEGIN
declare @output varchar(8000)
set @output = ''
Declare @vInputLength INT
Declare @vIndex INT
Declare @vCount INT
Declare @PrevLetter varchar(50)
SET @PrevLetter = ''
SET @vCount = 0
SET @vIndex = 1
SET @vInputLength = LEN(@pInput)
WHILE @vIndex <= @vInputLength
BEGIN
IF ASCII(SUBSTRING(@pInput, @vIndex, 1)) = ASCII(Upper(SUBSTRING(@pInput, @vIndex, 1)))
begin
if(@PrevLetter != '' and ASCII(@PrevLetter) = ASCII(Lower(@PrevLetter)))
SET @output = @output + ' ' + SUBSTRING(@pInput, @vIndex, 1)
else
SET @output = @output + SUBSTRING(@pInput, @vIndex, 1)
end
else
begin
SET @output = @output + SUBSTRING(@pInput, @vIndex, 1)
end
set @PrevLetter = SUBSTRING(@pInput, @vIndex, 1)
SET @vIndex = @vIndex + 1
END
return @output
END
具有fold的实现，也称为Aggregate:
public static string SpaceCapitals(this string arg) =>
new string(arg.Aggregate(new List<Char>(),
(accum, x) =>
{
if (Char.IsUpper(x) &&
accum.Any() &&
// prevent double spacing
accum.Last() != ' ' &&
// prevent spacing acronyms (ASCII, SCSI)
!Char.IsUpper(accum.Last()))
{
accum.Add(' ');
}
accum.Add(x);
return accum;
}).ToArray());
除了请求之外，这个实现还正确地保存了开头、内部、结尾空格和首字母缩写，例如，
" SpacedWord " => " Spaced Word ",
"Inner Space" => "Inner Space",
"SomeACRONYM" => "Some ACRONYM".
仅由ASCII字符组成的输入字符串的c#解决方案。regex结合了反向回溯来忽略出现在字符串开头的大写字母。使用Regex.Replace()返回所需的字符串。
参见regex101.com演示。
using System;
using System.Text.RegularExpressions;
public class RegexExample
{
public static void Main()
{
var text = "ThisStringHasNoSpacesButItDoesHaveCapitals";
// Use negative lookbehind to match all capital letters
// that do not appear at the beginning of the string.
var pattern = "(?<!^)([A-Z])";
var rgx = new Regex(pattern);
var result = rgx.Replace(text, " $1");
Console.WriteLine("Input: [{0}]\nOutput: [{1}]", text, result);
}
}
预期的输出:
Input: [ThisStringHasNoSpacesButItDoesHaveCapitals]
Output: [This String Has No Spaces But It Does Have Capitals]
更新:这里有一个变种，也将处理首字母缩写(大写字母序列)。
参见regex101.com演示和ideone.com演示。
using System;
using System.Text.RegularExpressions;
public class RegexExample
{
public static void Main()
{
var text = "ThisStringHasNoSpacesASCIIButItDoesHaveCapitalsLINQ";
// Use positive lookbehind to locate all upper-case letters
// that are preceded by a lower-case letter.
var patternPart1 = "(?<=[a-z])([A-Z])";
// Used positive lookbehind and lookahead to locate all
// upper-case letters that are preceded by an upper-case
// letter and followed by a lower-case letter.
var patternPart2 = "(?<=[A-Z])([A-Z])(?=[a-z])";
var pattern = patternPart1 + "|" + patternPart2;
var rgx = new Regex(pattern);
var result = rgx.Replace(text, " $1$2");
Console.WriteLine("Input: [{0}]\nOutput: [{1}]", text, result);
}
}
预期的输出:
Input: [ThisStringHasNoSpacesASCIIButItDoesHaveCapitalsLINQ]
Output: [This String Has No Spaces ASCII But It Does Have Capitals LINQ]
