Joã*_*elo 77
您应该通过删除不想要比较的字符来规范化每个字符串,然后您可以String.Equals使用StringComparison忽略的情况执行a .
像这样的东西:
string s1 = "HeLLo wOrld!";
string s2 = "Hello\n WORLd!";
string normalized1 = Regex.Replace(s1, @"\s", "");
string normalized2 = Regex.Replace(s2, @"\s", "");
bool stringEquals = String.Equals(
normalized1,
normalized2,
StringComparison.OrdinalIgnoreCase);
Console.WriteLine(stringEquals);
Regex.Replace首先使用此处删除所有空格字符.这两个字符串为null的特殊情况不在此处理,但您可以在执行字符串规范化之前轻松处理该情况.
删除所有不需要的字符,然后使用ToLower()方法忽略大小写.
编辑:虽然上述工作,但最好使用StringComparison.OrdinalIgnoreCase.只需将其作为方法的第二个参数传递Equals.
首先通过正则表达式从两个字符串中替换所有空格，然后使用String.Compare参数 ignoreCase = true的方法。
string a = System.Text.RegularExpressions.Regex.Replace("void foo", @"\s", "");
string b = System.Text.RegularExpressions.Regex.Replace("voidFoo", @"\s", "");
bool isTheSame = String.Compare(a, b, true) == 0;
如果您需要性能,此页面上的Regex解决方案对您来说运行速度太慢.也许你有一个想要排序的大型字符串列表.(然而,正则表达式解决方案更具可读性)
我有一个类,它查看两个字符串中的每个字符并比较它们,同时忽略大小写和空格.它不分配任何新字符串.它使用它char.IsWhiteSpace(ch)来确定空格,并char.ToLowerInvariant(ch)用于不区分大小写(如果需要).在我的测试中,我的解决方案运行速度比基于Regex的解决方案快5到8倍.我的类还在另一个SO答案中GetHashCode(obj)使用此代码实现IEqualityComparer的方法.这GetHashCode(obj)也忽略了空格并可选地忽略大小写.
这是我的班级:
private class StringCompIgnoreWhiteSpace : IEqualityComparer<string>
{
public bool Equals(string strx, string stry)
{
if (strx == null) //stry may contain only whitespace
return string.IsNullOrWhiteSpace(stry);
else if (stry == null) //strx may contain only whitespace
return string.IsNullOrWhiteSpace(strx);
int ix = 0, iy = 0;
for (; ix < strx.Length && iy < stry.Length; ix++, iy++)
{
char chx = strx[ix];
char chy = stry[iy];
//ignore whitespace in strx
while (char.IsWhiteSpace(chx) && ix < strx.Length)
{
ix++;
chx = strx[ix];
}
//ignore whitespace in stry
while (char.IsWhiteSpace(chy) && iy < stry.Length)
{
iy++;
chy = stry[iy];
}
if (ix == strx.Length && iy != stry.Length)
{ //end of strx, so check if the rest of stry is whitespace
for (int iiy = iy + 1; iiy < stry.Length; iiy++)
{
if (!char.IsWhiteSpace(stry[iiy]))
return false;
}
return true;
}
if (ix != strx.Length && iy == stry.Length)
{ //end of stry, so check if the rest of strx is whitespace
for (int iix = ix + 1; iix < strx.Length; iix++)
{
if (!char.IsWhiteSpace(strx[iix]))
return false;
}
return true;
}
//The current chars are not whitespace, so check that they're equal (case-insensitive)
//Remove the following two lines to make the comparison case-sensitive.
chx = char.ToLowerInvariant(chx);
chy = char.ToLowerInvariant(chy);
if (chx != chy)
return false;
}
//If strx has more chars than stry
for (; ix < strx.Length; ix++)
{
if (!char.IsWhiteSpace(strx[ix]))
return false;
}
//If stry has more chars than strx
for (; iy < stry.Length; iy++)
{
if (!char.IsWhiteSpace(stry[iy]))
return false;
}
return true;
}
public int GetHashCode(string obj)
{
if (obj == null)
return 0;
int hash = 17;
unchecked // Overflow is fine, just wrap
{
for (int i = 0; i < obj.Length; i++)
{
char ch = obj[i];
if(!char.IsWhiteSpace(ch))
//use this line for case-insensitivity
hash = hash * 23 + char.ToLowerInvariant(ch).GetHashCode();
//use this line for case-sensitivity
//hash = hash * 23 + ch.GetHashCode();
}
}
return hash;
}
}
private static void TestComp()
{
var comp = new StringCompIgnoreWhiteSpace();
Console.WriteLine(comp.Equals("abcd", "abcd")); //true
Console.WriteLine(comp.Equals("abCd", "Abcd")); //true
Console.WriteLine(comp.Equals("ab Cd", "Ab\n\r\tcd ")); //true
Console.WriteLine(comp.Equals(" ab Cd", " A b" + Environment.NewLine + "cd ")); //true
Console.WriteLine(comp.Equals(null, " \t\n\r ")); //true
Console.WriteLine(comp.Equals(" \t\n\r ", null)); //true
Console.WriteLine(comp.Equals("abcd", "abcd h")); //false
Console.WriteLine(comp.GetHashCode(" a b c d")); //-699568861
//This is -699568861 if you #define StringCompIgnoreWhiteSpace_CASE_INSENSITIVE
// Otherwise it's -1555613149
Console.WriteLine(comp.GetHashCode("A B c \t d"));
}
这是我的测试代码(使用Regex示例):
private static void SpeedTest()
{
const int loop = 100000;
string first = "a bc d";
string second = "ABC D";
var compChar = new StringCompIgnoreWhiteSpace();
Stopwatch sw1 = Stopwatch.StartNew();
for (int i = 0; i < loop; i++)
{
bool equals = compChar.Equals(first, second);
}
sw1.Stop();
Console.WriteLine(string.Format("char time = {0}", sw1.Elapsed)); //char time = 00:00:00.0361159
var compRegex = new StringCompIgnoreWhiteSpaceRegex();
Stopwatch sw2 = Stopwatch.StartNew();
for (int i = 0; i < loop; i++)
{
bool equals = compRegex.Equals(first, second);
}
sw2.Stop();
Console.WriteLine(string.Format("regex time = {0}", sw2.Elapsed)); //regex time = 00:00:00.2773072
}
private class StringCompIgnoreWhiteSpaceRegex : IEqualityComparer<string>
{
public bool Equals(string strx, string stry)
{
if (strx == null)
return string.IsNullOrWhiteSpace(stry);
else if (stry == null)
return string.IsNullOrWhiteSpace(strx);
string a = System.Text.RegularExpressions.Regex.Replace(strx, @"\s", "");
string b = System.Text.RegularExpressions.Regex.Replace(stry, @"\s", "");
return String.Compare(a, b, true) == 0;
}
public int GetHashCode(string obj)
{
if (obj == null)
return 0;
string a = System.Text.RegularExpressions.Regex.Replace(obj, @"\s", "");
return a.GetHashCode();
}
}
小智 5
这也可能起作用。
String.Compare(s1, s2, CultureInfo.CurrentCulture, CompareOptions.IgnoreCase | CompareOptions.IgnoreSymbols) == 0
编辑：
IgnoreSymbols：指示字符串比较必须忽略符号，例如空格字符，标点符号，货币符号，百分号，数学符号，“与”号等。
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