Passing char array to fuction

[taurus]

I have this:

#include "func.h"

int main()
{
	char array[5] = "hello";
	func(array);
}

in another file I have:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <sys/types.h>
#include <dirent.h>

#include "pgmfile.h"
#include "malloc_image.h"

void func(char array[])
{
	printf("%s\n", array);
}

but when i run it it prints hello along with other characters. why. what can i do?

[kermit]

I have this:

#include "func.h"

int main()
{
	char array[5] = "hello";
	func(array);
}

but when i run it it prints hello along with other characters. why. what can i do?

Your array has five elements, but you actually need six (one for the terminating nul character '\0').

[BEN10]

I have this:

#include "func.h"

int main()
{
	char array[5] = "hello";
	func(array);
}

Initializing more elements in the array than its size is an error except for char where it's not. The '\0' terminator will not get stored and thus after printing hello it doesn't know where to stop and prints unwanted chars after that too.

[kairozamorro]

In the function store the char array in a string and print the string?

[bithub]

In the function store the char array in a string and print the string?

A char array is a string...

[kairozamorro]

Yes, but to avoid the extra characters, etc.

[quzah]

A char array is a string...

No if it doesn't have a null terminator it's not.


Quzah.

[bithub]

No if it doesn't have a null terminator it's not.


Quzah.

How enlightening...

[quzah]

How enlightening...

Well considering the array in the OP isn't a string, yes, yes it was.


Quzah.

[bithub]

Well considering the array in the OP isn't a string, yes, yes it was.


Quzah.

Cool, then explain to me how you can null terminate that from within the function:

void func(char array[])
{
	/* convert this char array to a string before the print */
	printf("%s\n", array);
}

[quzah]

You don't. I know you're trying to be clever here, but you aren't. At all. You have to know the answer to this. You cannot know the size of an array once it is passed to a function. You cannot guarantee that array is a string.

You aren't passing the size, so you can only assume. You might be right, you might not.

char oops[1] = {'x'};
...
func( oops );

Perfectly legal.


Quzah.

[bithub]

You don't. I know you're trying to be clever here, but you aren't. At all. You have to know the answer to this. You cannot know the size of an array once it is passed to a function. You cannot guarantee that array is a string.

You aren't passing the size, so you can only assume. You might be right, you might not.

char oops[1] = {'x'};
...
func( oops );

Perfectly legal.


Quzah.

Exactly. Now look at my first post in the context of what I quoted. My point is that you can't convert a char array to a string in the function because to the function there is no difference. The function must assume that the passed array is a string.

[quzah]

Exactly. Now look at my first post in the context of what I quoted. My point is that you can't convert a char array to a string in the function because to the function there is no difference. The function must assume that the passed array is a string.

Well that's not exactly true. If you know the size of an array, which you could do by including it as an argument, you can make it a string any time you want by adding a terminating null anywhere < size.

But pretty much we were both trying to get the same point across to them, so I see what you were saying.


Quzah.