設計&程式

replacing text function in C++

/* replaces every occurrence of c1 in str with c2 */
void replace( char *str, char c1, char c2 )
{
unsigned int i;
for( i = 0; i < strlen( str ); i++ )
if( str == c1 )
str = c2;
}
/* replaces every occurrence of c1 in str with c2 */

As Chris has pointed out this function will only work if str contains the string c1, in which case it will be changed to c2.

I know you want to create and optimise your own functions but I suggest you try something like this example:

#include "string.h"
#include "stdio.h"

char str[] = "lazy";
char string[] = "The quick brown dog jumps over the lazy fox";
char fmt1[] = " 1 2 3 4 5";
char fmt2[] = "12345678901234567890123456789012345678901234567890";

int main( void )
{
char *pdest;
int result;
printf( "String to be searched:\n %s\n", string );
printf( " %s\n %s\n\n", fmt1, fmt2 );
pdest = strstr( string, str );
result = (int)(pdest - string + 1);
if ( pdest != NULL )
printf( "%s found at position %d\n", str, result );
else
printf( "%s not found\n", str );
}

Found this example here:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_crt_strstr.2c_.wcsstr.2c_._mbsstr.asp