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Case-Insensitive String Replace

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25 Jan 2000CPOL 155.5K   14   25
Function to replace all occurences of a string within another, ignoring the case

Introduction

This is a simple function that acts like CString::Replace(), except that the case of the string to search for is ignored.

The whole code follows:

C++
// instr:  string to search in.
// oldstr: string to search for, ignoring the case.
// newstr: string replacing the occurrences of oldstr.
CString ReplaceNoCase( LPCTSTR instr, LPCTSTR oldstr, LPCTSTR newstr )
{
	CString output( instr );

	// lowercase-versions to search in.
	CString input_lower( instr );
	CString oldone_lower( oldstr );
	input_lower.MakeLower();
	oldone_lower.MakeLower();

	// search in the lowercase versions,
	// replace in the original-case version.
	int pos=0;
	while ( (pos=input_lower.Find(oldone_lower,pos))!=-1 ) {

		// need for empty "newstr" cases.
		input_lower.Delete( pos, lstrlen(oldstr) );	
		input_lower.Insert( pos, newstr );

		// actually replace.
		output.Delete( pos, lstrlen(oldstr) );
		output.Insert( pos, newstr );
	}

	return output;
}

The function's implementation is rather simple: it creates several copies of the strings. If you need a memory- and speed- optimized replace function, this one is probably not the best for you. Anyway, in my project, it worked just well.

Please feel free to ask any questions you have by e-mail: keim@zeta-software.de.

History

  • 25th January, 2000: Initial post

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Chief Technology Officer Zeta Software GmbH
Germany Germany
Uwe does programming since 1989 with experiences in Assembler, C++, MFC and lots of web- and database stuff and now uses ASP.NET and C# extensively, too. He has also teached programming to students at the local university.

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In his free time, he does climbing, running and mountain biking. In 2012 he became a father of a cute boy and in 2014 of an awesome girl.

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Comments and Discussions

 
GeneralRe: Includes/Namespaces? Pin
Lord Kixdemp6-Sep-05 10:09
Lord Kixdemp6-Sep-05 10:09 
GeneralRe: Includes/Namespaces? Pin
Christian Graus6-Sep-05 11:08
protectorChristian Graus6-Sep-05 11:08 
GeneralRe: Includes/Namespaces? Pin
Lord Kixdemp7-Sep-05 11:27
Lord Kixdemp7-Sep-05 11:27 
GeneralRe: Includes/Namespaces? Pin
Christian Graus7-Sep-05 12:47
protectorChristian Graus7-Sep-05 12:47 
GeneralRe: Includes/Namespaces? Pin
Lord Kixdemp8-Sep-05 13:22
Lord Kixdemp8-Sep-05 13:22 
GeneralRe: Includes/Namespaces? Pin
Christian Graus8-Sep-05 13:27
protectorChristian Graus8-Sep-05 13:27 
QuestionBug correction? Pin
petermcwerner28-Jul-05 1:35
petermcwerner28-Jul-05 1:35 
AnswerRe: Bug correction? Pin
AberAber26-Nov-13 18:22
AberAber26-Nov-13 18:22 
GeneralBug Pin
petermcwerner27-Jul-05 8:18
petermcwerner27-Jul-05 8:18 
Generalwhy MakeLower() can not work Pin
David 200817-Mar-04 6:30
David 200817-Mar-04 6:30 
GeneralBug Pin
Wicket_19-Feb-03 20:53
sussWicket_19-Feb-03 20:53 
GeneralRe: Bug Pin
wicket_19-Feb-03 20:56
susswicket_19-Feb-03 20:56 
Generala little optimization Pin
KarstenK15-Apr-02 21:17
mveKarstenK15-Apr-02 21:17 
GeneralRe: a little optimization Pin
Uwe Keim15-Apr-02 21:23
sitebuilderUwe Keim15-Apr-02 21:23 
GeneralGood but a little bit slow Pin
Braulio Dez22-Nov-01 22:33
Braulio Dez22-Nov-01 22:33 

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