Comparing strings - a few samples
I thought I would share some simple sample code which is useful for finding problems in string content. Here are three methods I wrote which are useful to see whats in a string and differences between strings. I use these with a simple program which uses two text boxes for pasting text into and a third window for displaying results. Please note that I'm not using stringbuilder here on purpose - I do avoid it when writting code which i want to be as simple and language generic as possible (I would use stringbuilder if I were writting a production app of course). I hope you find these useful.
The routines:
CompareStrings() will compare two different strings and tell you about differences.
DumpString() Will dump out the string in a Hex Dump.
GetStringStats() Provides information on the characters which are in a string.
Samples:
//*************************************************************************************
//GetStringStats() Provides information on the characters which are in a string.
//*************************************************************************************
private string GetStringStats(string sString)
{
string sResults = string.Empty;
char[] CharArr = sString.ToCharArray();
//int iCharCode = 0;
int iTotalLines = 0;
int iTotalCharacters = 0;
int iCurrentLine = 0;
int iCurrentLineLength = 0;
int iLongestLine = 0;
int iLongestLineChars = 0;
int iStandardEnglish = 0;
int iNull = 0;
int iTab = 0;
int iCr = 0;
int iLF = 0;
int iLowerCaseAlpha = 0;
int iUpperCaseAlpha = 0;
int iNumeric = 0;
int iAbove255 = 0;
int iAbove127 = 0;
int iControlCharacters = 0;
char xChar = ' ';
long ixChar = 0;
iTotalCharacters = sString.Length;
for (int iCount = 0; iCount < sString.Length; iCount++)
{
xChar = CharArr[iCount];
iCurrentLineLength++;
if (xChar == '\n' || xChar == '\r')
{
if (xChar == '\n')
{
iCurrentLine++;
iTotalLines++;
}
iCurrentLineLength = 0;
}
if (iCurrentLineLength > iLongestLineChars)
{
iLongestLineChars = iCurrentLineLength;
iLongestLine = iCurrentLine;
}
ixChar = (int)xChar;
if (xChar >= 'a' && xChar <= 'z') iLowerCaseAlpha++;
if (xChar >= 'A' && xChar <= 'Z') iUpperCaseAlpha++;
if (xChar >= '0' && xChar <= '9') iNumeric++;
if (ixChar > 255) iAbove255++;
if (ixChar > 127) iAbove127++;
if (ixChar <= 31) iControlCharacters++;
if (ixChar > 31 & ixChar < 127 || xChar == '\r' || xChar == '\n' || xChar == '\t')
{
iStandardEnglish++;
}
if (xChar == '\0') iNull++;
if (xChar == '\t') iTab++;
if (xChar == '\r') iCr++;
if (xChar == '\n') iLF++;
}
sResults += " Total Lines: " + iTotalLines.ToString() + " ";
sResults += "Total Characters: " + iTotalCharacters.ToString() + " ";
sResults += "Longest Line is " + iLongestLine.ToString() + " having " + iLongestLineChars.ToString() + " characters\r\n";
sResults += "\r\n";
sResults += " Characters:\r\n";
sResults += string.Format(" {0} In Normal English Range - letters, numbers, symbols and Cr/Lf/Tab (31-126 dec range+ 13/10/9 dec) \r\n", iStandardEnglish.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Tab(09 hex)\r\n", iTab.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Cr (0D hex)\r\n", iCr.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Lf (0A hex)\r\n", iLF.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Control Characters (Range 0-31 dec/0-1F Hex)\r\n", iControlCharacters.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Above 127 dec range\r\n", iAbove255.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Above 255 dec range\r\n", iAbove127.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Null (00 hex)\r\n", iNull.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Lower Case\r\n", iLowerCaseAlpha.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Upper Case\r\n", iUpperCaseAlpha.ToString().PadLeft(6, ' '));
sResults += string.Format(" {0} Numeric\r\n", iNumeric.ToString().PadLeft(6, ' '));
sResults += "\r\n";
return sResults;
}
//****************************************************************
// DumpString() Will dump out the string in a Hex Dump.
//****************************************************************
private string DumpString(string sString)
{
string sResults = string.Empty;
char[] CharA = sString.ToCharArray();
string sChar = " ";
int iCharCode = 0;
string sHex = "";
string sLeft = "";
string sRight = "";
int iLine = 0;
sResults = " 0000 0001 0002 0003 0004 0005 0006 0007 0008 0009 000A 000B 000C 000D 000E 000F 0123456789ABCDEF\r\n";
sResults += "-------+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+----+ +----------------\r\n";
for (int iCount = 0; iCount < sString.Length; iCount++)
{
char x = CharA[iCount];
if ((CharA[iCount] != '\n') &&
(CharA[iCount] != '\r') &&
(CharA[iCount] != '\0') &&
(CharA[iCount] != '\t'))
{
sChar = CharA[iCount].ToString();
}
else
{
sChar = " ";
}
iCharCode = Convert.ToInt32(CharA[iCount]);
sHex = String.Format("{0:X}", iCharCode);
sHex = sHex.PadLeft(4, '0');
sLeft += sHex + " ";
sRight += sChar;
//sResults += "" + sHex + " " + sChar + " " ;
if (iCount % 16 == 15)
{
sResults += String.Format("{0:X}", iLine).PadLeft(6, '0') + " " + sLeft + " " + sRight + "\r\n";
sLeft = "";
sRight = "";
iLine++;
}
}
if (sLeft.Length != 0)
{
sResults += String.Format("{0:X}", iLine).PadLeft(6, '0') + " ";
sResults += sLeft.PadRight(80,' ') + " " + sRight + "\r\n";
}
sResults = sResults.TrimEnd();
sResults += "\r\n";
return sResults;
}
//****************************************************************************************
// CompareStrings() will compare two different strings and tell you about differences...
//****************************************************************************************
private string CompareStrings(string StringA, string StringB)
{
string sResults = string.Empty;
int iComp = 0;
//int iLength = 0;
StringA = txtFirstString.Text;
StringB = txtSecondString.Text;
sResults += "First String Length: " + StringA.Length.ToString();
sResults += " ";
sResults += "Second String Length: " + StringB.Length.ToString();
sResults += "\r\n";
iComp = StringA.CompareTo(StringB);
if (iComp < 0)
sResults += "Value of First String is LESS THAN (<) Second String.\r\n";
if (iComp == 0)
sResults += "Value of First String is EQUAL TO (=) Second String.\r\n";
if (iComp > 0)
sResults += "Value of First String is GREATER THAN (>) Second String.\r\n";
Boolean bResultFound = false;
char[] CharA = StringA.ToCharArray();
char[] CharB = StringB.ToCharArray();
string sLineA = "";
string sLineB = "";
int iLineCount = 1;
int iCharInLineCount = 1;
int iLongestLineCharCount = 0;
int iLongestLineAtLine = 0;
// Value of First String is LESS THAN (<) Second String or the strings are equal...
if (StringA.Length <= StringB.Length)
{
sResults += "\r\n*** First String VS Second String ***\r\n";
for (int iCount = 0; iCount < StringA.Length; iCount++)
{
if (CharA[iCount] != '\n' && CharA[iCount] != '\r')
{
sLineA += CharA[iCount].ToString();
}
if (CharB[iCount] != '\n' && CharB[iCount] != '\r')
{
sLineB += CharB[iCount].ToString();
}
iCharInLineCount++;
if (CharA[iCount] != CharB[iCount])
{
if (bResultFound == false)
{
sResults += "Found difference at string position: " + (int)(iCount + 1);
sResults += " ...Hex: " + String.Format("{0:X6}", (iCount / 16)) + " + " + String.Format("{0:X2}", (iCount % 16) );
sResults += " - Refer to Hex Dump below.";
sResults += "\r\n";
sResults += " Line: '" + iLineCount.ToString() + "' ";
sResults += " Char: '" + sLineA.Length.ToString() + "' \r\n";
sResults += " First String Char: '" + CharA[iCount].ToString() + "' ";
sResults += " Second String Char: '" + CharB[iCount].ToString() + "' \r\n";
sResults += " Start of First String: '" + sLineA + "' \r\n";
sResults += " Start of Second String: '" + sLineB + "' \r\n";
//sResults += " Character pos in stream: '" + iCount.ToString() + "' \r\n";
sResults += "\r\n";
bResultFound = true;
}
}
if (CharA[iCount] == '\n' || CharA[iCount] == '\r')
{
sLineA = "";
sLineB = "";
if (CharA[iCount] == '\n')
{
iLineCount++;
iCharInLineCount = 1;
}
}
}
}
// Value of First String is GREATER THAN (>) Second String.
if (StringA.Length > StringB.Length)
{
sResults += "\r\n*** Second String VS First String ***\r\n";
for (int iCount = 0; iCount < StringB.Length; iCount++)
{
if (CharA[iCount] != '\n' && CharA[iCount] != '\r')
{
sLineA += CharA[iCount].ToString();
}
if (CharB[iCount] != '\n' && CharB[iCount] != '\r')
{
sLineB += CharB[iCount].ToString();
}
iCharInLineCount++;
if (CharA[iCount] != CharB[iCount])
{
if (bResultFound == false)
{
sResults += "Found difference at position: " + (int)(iCount + 1);
sResults += " ...Hex: " + String.Format("{0:X6}", (iCount / 16)) + " + " + String.Format("{0:X2}", (iCount % 16) );
sResults += " - Refer to Hex Dump below.";
sResults += "\r\n";
sResults += " Line: '" + iLineCount.ToString() + "' ";
sResults += " Char: '" + sLineA.Length.ToString() + "' \r\n";
sResults += " First String Char: '" + CharA[iCount].ToString() + "' ";
sResults += " Second String Char: '" + CharB[iCount].ToString() + "' \r\n";
sResults += " Start of First String: '" + sLineA + "' \r\n";
sResults += " Start of Second String: '" + sLineB + "' \r\n";
sResults += "\r\n";
bResultFound = true;
}
}
if (CharB[iCount] == '\n' || CharB[iCount] == '\r')
{
sLineA = "";
sLineB = "";
if (CharB[iCount] == '\n')
{
iLineCount++;
iCharInLineCount = 1;
}
}
if (iCharInLineCount > iLongestLineCharCount)
{
iLongestLineCharCount = iCharInLineCount;
iLongestLineAtLine = iLineCount;
}
}
}
if (bResultFound == false)
{
if (StringA.Length > StringB.Length)
{
sResults += "The difference is in what is in first string and not in second string... \r\n";
sResults += " * The first string is longer by " + String.Format("{0}", (StringA.Length - StringB.Length)) + " characters.\r\n";
}
if (StringA.Length < StringB.Length)
{
sResults += "The difference is in what is in second string and not in first string... \r\n";
sResults += " * The second string is longer by " + String.Format("{0}", (StringB.Length - StringA.Length)) + " characters.\r\n";
}
}
return sResults;
}