How do I peform this to an array?

**dwks** · 11-07-2007

That's a sure sign of a string without a NULL terminator. Add one in, see what happens.

**Fredir** · 11-07-2007

I see...
exactly where should I include

Code:

result[i + times] = 0;

I tried putting into the loop, but it was causing the conversion part not to work at all.

If i put it outside, it just says i is not identified.

**matsp** · 11-07-2007

Aside from the several points that dwks pointed out, this will not work right:

Code:

		if (line [i] == 's')
		{
			result[i] = 'z';
		}

Where are you writing the z? Is that REALLY where you want to write it, assuming your input is "resolved result"? Step through it manually and see what happens [or with a debugger if you know how to use one].

--
Mats

**matsp** · 11-07-2007

Originally Posted by Fredir

I see...
exactly where should I include

Code:

result[i + times] = 0;

I tried putting into the loop, but it was causing the conversion part not to work at all.

If i put it outside, it just says i is not identified.

Move the "int i" to outside the for-loop and it will work better.

--
Mats

**anon** · 11-07-2007

Code:

		if (line [i] == 's')
		{
			result[i + times] = 'z';
		}
		else if (line[i] == 'r')
		{
               ...

These are one thing. You'll also need to null-terminate the result and make sure it is as large as needed.

Of cource, everything would be easier if you used C++ strings all the way:

Code:

#include <iostream>
#include <string>

int main()
{
    std::string source;
    std::getline(std::cin, source);
    std::string dest;
    for (std::size_t i = 0; i != source.size(); ++i) {
        switch (source[i]) {
            case 's': dest += 'z'; break;
            case 'r': dest += "rr"; break;
            default: dest += source[i];
        }
    }
    std::cout << source << '\n' << dest << '\n';
}

**Fredir** · 11-07-2007

Oh the light!

You all have been extremely helpful, thanks for all those inputs.

I did what you suggested, and it seems to be working.

here is the updated version:

Code:

// C-String Lab.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <string>

using namespace std;

#define MAX_SIZE 200



int main()
{

	int index = 0;
	int times = 0;

	char line[MAX_SIZE];

	cin.getline(line, 200);
	cout << "You entered: " << line << endl;
	string str(line);
	cout << "The size of the line is " << str.size() << " characters.\n";


	char result [256];
	int i;
	for (i=0; i < str.size(); i++)
	{
		if (line [i] == 's')
		{
			result[i + times] = 'z';
		}
		
	    else if (line[i] == 'r')
		{
			result[i + times] = 'r';
			result[i + times + 1] = 'r';
			times ++;
		}
		else 
		{
			result[i + times] = line[i];
		}
	
		
	}
	result[i + times] = 0;
	cout << result << endl;

//	char* dest = new char[newSize + 1];




	return 0;
}

the next thing I have to do is to replace every "th" in the string with a "z". Would I be able to do this just by include another if stamement or should I create another for loop with result since I will be shifting indexes again?

**Fredir** · 11-07-2007

One final question:

for the array result,

I tried making it

char result [str. length() * 2] so it would be dynamically allocated. But i got an error saying size of result cannot be 0. I am assuming this is happening because I only get an actual length once the user inputs it. But, how could I accomplish something of that effect?

**dwks** · 11-07-2007

You could do it in that loop. It wouldn't be too difficult. Something like this:

Code:

if(array[index] == 't' && array[index+1] == 'h') {
    result[rindex] = 'z';
}

Also note what I said above about not needing to create an entirely new std::string. You could do this instead:

Code:

	int i, len = strlen(line);
	for (i=0; i < len; i++)

You'd have to include <cstring>, which is where strlen() is located. And you could drop <string>, as yuo wouldn't be using any std::strings.

[edit]

I tried making it

char result [str. length() * 2] so it would be dynamically allocated. But i got an error saying size of result cannot be 0. I am assuming this is happening because I only get an actual length once the user inputs it. But, how could I accomplish something of that effect?

I don't think you can declare variable-sized arrays in standard C++. Try this instead:

Code:

char *result = new char[str.length() * 2];

// ...

delete [] result;

I'd use str.length()*2+1 for the size, though, because that's the maximum it could be. Don't forget the NULL.

[/edit]

**Fredir** · 11-07-2007

Code:

for (k =0; k < size of result; i++)
{
if (result[k] == 't' && result[k+1] == 'h')
 newResult[k] == 'z';
}

--> does this seem to be in the right track?

[EDIT] thanks dwks, I guess I had the idea...let me incorporate those things in...

**Fredir** · 11-07-2007

I don't think the if statement is working... I will see if I can do the above loop later:

Code:

// C-String Lab.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <string>

using namespace std;

#define MAX_SIZE 200



int main()
{

	int index = 0;
	int times = 0;

	char line[MAX_SIZE];

	cin.getline(line, 200);
	cout << "You entered: " << line << endl;
	string str(line);
	cout << "The size of the line is " << str.size() << " characters.\n";


	char result [256];
	int i;
	
	for (i=0; i < str.size(); i++)
	{
		if (line [i] == 's')
		{
			result[i + times] = 'z';
		}
		
	    else if (line[i] == 'r')
		{
			result[i + times] = 'r';
			result[i + times + 1] = 'r';
			times ++;
		}
		if (result[i] == 't' && result[i+1] == 'h')
		{
			result[i] == 'z';
		}
		else 
		{
			result[i + times] = line[i];
		}
		
		
	}
	result[i + times] = 0;
	cout << result << endl;

//	char* dest = new char[newSize + 1];




	return 0;
}

**matsp** · 11-07-2007

Code:

else if (line[i] == 'r')
...
if (result[i] == 't' && result[i+1] == 'h')

See anything different.

--
Mats

**Elysia** · 11-07-2007

The code doesn't take unicode into mind either. It's good practice to try to use TCHAR functions and _T() macro to make it both unicode/ansi safe. It takes some getting used to, I've found out.

**Fredir** · 11-07-2007

Ok, looks like I completed the code. Here is the final version:

Code:

#include "stdafx.h"
#include <iostream>
#include <cstring>

using namespace std;

#define MAX_SIZE 200



int main()
{

	int index = 0;
	int times = 0;

	char line[MAX_SIZE];

	cin.getline(line, MAX_SIZE);
	cout << "You entered: " << line << endl;
	cout << "The size of the line is " << strlen(line) << " characters.\n";

	int len = strlen(line);
	char* result = new char[len*2 +1];
	int i;

	for (i=0; i < len; i++)
	{
		if (line [i] == 's')
		{
			result[i + times] = 'z';
		}
		else if (line[i] == 'r')
		{
			result[i + times] = 'r';
			result[i + times + 1] = 'r';
			times ++;
		}
		else if (line[i] == 't' && line[i+1] == 'h')
		{
			result[i + times] = 'z';
		}
		else 
		{
			result[i + times] = line[i];
		}


	}

	result[i + times] = 0;
	cout << "Translation: " << result << endl;
	delete [] result;


	return 0;
}

Thank you all for the help. If anyone wants to give tips as how to make the code more efficient for my own benefit in the future, that would be nice.

**dwks** · 11-07-2007

Your code is pretty good now. One of my only suggestions is this:

Code:

	cout << "The size of the line is " << strlen(line) << " characters.\n";

	int len = strlen(line);

Swap those lines, and you can use the variable len in the cout. strlen() does take a little while to execute, so your program will be marginally more efficient if you do as I suggest.

Originally Posted by Elysia

The code doesn't take unicode into mind either. It's good practice to try to use TCHAR functions and _T() macro to make it both unicode/ansi safe. It takes some getting used to, I've found out.

Both of those are Windows-only functions. You shouldn't recommend them in a program that is otherwise perfectly standard C++. On the other hand, because the OP is including "stdafx.h", they're clearly using a Windows compiler (probably MSVC). Still, when you recommend things like that, at least mention in passing that they're Windows-specific.

**Elysia** · 11-08-2007

Originally Posted by dwks

Both of those are Windows-only functions. You shouldn't recommend them in a program that is otherwise perfectly standard C++. On the other hand, because the OP is including "stdafx.h", they're clearly using a Windows compiler (probably MSVC). Still, when you recommend things like that, at least mention in passing that they're Windows-specific.

Unicode Windows-specific? Last I looked, using TCHAR resolved to either CHAR or WCHAR_T and ANSI/UNICODE C/C++ standard functions (as well as Windows-only API).