Thread: Dropping the first character of a string

Code:

int main()
{
	std::string buffer("Spaghetti");
	buffer.erase(0,1);
	std::cout << buffer << std::endl;

	return 0;
}

Originally Posted by suzumebachi

e:\dev\textfile\textfile.cpp(36) : error C2679: binary '<<' : no operator defined which takes a right-hand operand of type 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >' (or there is no acceptable convers
ion)

The following should be assumed for the code sample provided to work properly...

Code:

#include <string>
#include <iostream>

huzzah it works! thanks guys...

Code:

int main()
{
	int length;
	char capital;
	char text[]="this is some text";
	char space[]=" ";
	char *result=NULL;

	result = strtok(text,space);
	while (result != NULL)
	{
		length = strlen(result);
		strncpy(&capital, result, 1);
		std::cout << (char)toupper( (int)capital );
		std::string buffer(result);
		buffer.erase(0,1);
		std::cout << buffer << " ";
		result = strtok( NULL, space );
	}
	return 0;
}

edit: ok the above works fine, but if i try to turn it into a seperate function it compiles just fine but crashes when you try to run it:

Code:

void propercase(char input[])
{
	int length;
	char capital;
	char space[]=" ";
	char *result=NULL;

	result = strtok(input,space);
	while (result != NULL)
	{
		length = strlen(result);
		strncpy(&capital, result, 1);
		std::cout << (char)toupper( (int)capital );
		std::string buffer(result);
		buffer.erase(0,1);
		std::cout << buffer << " ";
		result = strtok( NULL, space );
	}
}

int main()
{
	propercase("this is some text");
	return 0;
}

Code:

strncpy(&capital, result, 1);

Why not just:

Code:

capital = result[0];

Code:

std::string buffer(result);
buffer.erase(0,1);
std::cout << buffer << " ";

If all you are trying to do here is display the "remainder" of the word (less the first character you are converting to uppercase) you could have either just converted the remainder to a string directly (skipping the erase bit):

Code:

std::string buffer(result+1);

Or you don't really need to even bother going through the motions of converting it to a string at all just so you can easily remove the first character and have something to display. You can just output the remainder directly using cout without converting it to a string:

Code:

std::cout << result+1 << " ";

A more C++/OO version of this program would likely use a stringstream and the standard stream extraction operators in place of the strtok function.

Code:

#include <sstream>
#include <iostream>
#include <string>
#include <cctype>

int main()
{
    std::stringstream sstr("this is some text");
    std::string word;

    while( sstr >> word )
        std::cout << (char)toupper(word[0]) << word.substr(1) << " ";

    return 0;
}

On to your problem:

Originally Posted by suzumebachi

edit: ok the above works fine, but if i try to turn it into a seperate function it compiles just fine but crashes when you try to run it:

I suspect this is because you are passing a string literal into the function directly which is placed in read only memory. The strtok function needs to modify this data and can't if it is read only. You need to create an actual char array and then pass that in to the function. I.e. change this...

Code:

int main()
{
    propercase("this is some text");  // This is a string literal, i.e. read-only memory
    return 0;
}

Into this...

Code:

int main()
{
    char text[] = "this is some text";
    propercase(text);
    return 0;
}