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
这对聚合来说是个好机会。它被设计成可读的，但不一定特别快。
someString
.Aggregate(
new StringBuilder(),
(str, ch) => {
if (char.IsUpper(ch) && str.Length > 0)
str.Append(" ");
str.Append(ch);
return str;
}
).ToString();
其他回答
没有测试性能，但在linq的一行中:
var val = "ThisIsAStringToTest";
val = string.Concat(val.Select(x => Char.IsUpper(x) ? " " + x : x.ToString())).TrimStart(' ');
你拥有的一切都很完美。只需要记住将value重新赋值给这个函数的返回值即可。
value = System.Text.RegularExpressions.Regex.Replace(value, "[A-Z]", " $0");
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
我把Kevin Strikers优秀的解决方案转换为VB。由于我被锁定在。net 3.5，我还必须写IsNullOrWhiteSpace。这通过了他所有的测试
<Extension()>
Public Function IsNullOrWhiteSpace(value As String) As Boolean
If value Is Nothing Then
Return True
End If
For i As Integer = 0 To value.Length - 1
If Not Char.IsWhiteSpace(value(i)) Then
Return False
End If
Next
Return True
End Function
<Extension()>
Public Function UnPascalCase(text As String) As String
If text.IsNullOrWhiteSpace Then
Return String.Empty
End If
Dim newText = New StringBuilder()
newText.Append(text(0))
For i As Integer = 1 To text.Length - 1
Dim currentUpper = Char.IsUpper(text(i))
Dim prevUpper = Char.IsUpper(text(i - 1))
Dim nextUpper = If(text.Length > i + 1, Char.IsUpper(text(i + 1)) Or Char.IsWhiteSpace(text(i + 1)), prevUpper)
Dim spaceExists = Char.IsWhiteSpace(text(i - 1))
If (currentUpper And Not spaceExists And (Not nextUpper Or Not prevUpper)) Then
newText.Append(" ")
End If
newText.Append(text(i))
Next
Return newText.ToString()
End Function
private string GetProperName(string Header)
{
if (Header.ToCharArray().Where(c => Char.IsUpper(c)).Count() == 1)
{
return Header;
}
else
{
string ReturnHeader = Header[0].ToString();
for(int i=1; i<Header.Length;i++)
{
if (char.IsLower(Header[i-1]) && char.IsUpper(Header[i]))
{
ReturnHeader += " " + Header[i].ToString();
}
else
{
ReturnHeader += Header[i].ToString();
}
}
return ReturnHeader;
}
return Header;
}
